Rao was a lecturer in English before joining the government service through an all-India competition in 1957. He joined the Indian Audit and Accounts Service from which he retired as Director General in November 1990.

More interested in games and sports than in astrology in his youth, Rao won brilliancy prizes in chess competitions and two state championships in bridge competitions. He played ten other games which is why in his astrological writings also there are references to games often.

During his service career, he was the planner, organizer and teacher of three international courses on Audit of Receipts as a joint director once and director twice.

His interactions with foreigners have been both on professional and astrological levels for more than two decades which is why he has, as an astrologer, a large international network of friends. He went on doing all his fundamental researches in astrology during his service career because of which, he went on collecting horoscopes systematically in thousands.

He has in his possession more than 50,000 horoscopes with ten important events of each individual noted with him. It is perhaps, the largest individual collection of horoscopes any astrologer perhaps has.

The strain of doing astrology as a mission, not charging any fee, almost made him give up astrology many times. But in December 1981, he was forced out of his shell to participate in a three-day seminar on astrology in Delhi. After this ground breaking speech, there has been a persistent demand for his astrological articles. From then onwards he has been sharing with his readers his original researches for which he has won worldwide praise.

Between 1993 and 1995, Rao has visited the USA on five lecture tours. He was the Chief Guest at the Second Conference of the American Council of Vedic Astrology in 1993. He was requested to be present in the Third Conference also in 1994 on the opening day because of the crowds he would draw. His name was advertised till November 1995 also for the Fourth Conference though he had made it clear that he would not be available anymore for the American conferences. As a result of his academic approach, he has now more than a thousand students in India and more than two hundred in the USA.

He is the Advisor of Astrology Courses in the Bharatiya Vidya Bhawan, New Delhi. The teachers on the teaching faculty of the astrology course in the Bharatiya Vidya Bhawan have, like him, never charged any fees for teaching which they do in an honorary capacity.

What impelled Rao to do it is well explained in his own horoscope where the lagna and the 10th lords get combined in the lagna, with an exalted Jupiter in the 10th house.

All this was foreseen by his Jyotish Guru, Yogi Bhaskarananda of Gujarat whom Rao describes as the last of the Rishi astrologers in the purest classical mould. He had told him that he would have to visit many foreign countries to give to Hindu astrology the honour, recognition and dignity which it did not have till then. An American summed up the impact of the first ever foreign visit of Rao to the USA in 1993 as, “Vedic astrology before Rao and after Rao”.

What different yogis have said about astrology as a Vedanga which he must not give up has been quoted in his book, Yogis, Destiny and the Wheel of Time. Astrology is ill-reputed as a profession because of its mercenary and exploitative nature.

Rao's desire never to turn into a professional astrologer, has won him thousands of admirers and also some enemies from the community of professional astrologers who felt threatened, when around him there grew up a fine team of more than two hundred academic astrologers like him, for whom astrology is not a source of living, but a super science to delve into the meaning and purpose of human life, which is what astrology, as Vedanga, should and has to be.

Both his mantra guru, Swami Paramananda Saraswati, and his jyotish guru, Yogi Bhaskarananda, taught him some secrets of spiritual astrology which are not given usually in any book of astrology. Rao has revealed some of these secrets in his book, "Yogis, Destiny and the Wheel of Time".

Among Rao’s recent fundamental and most original researches are his two books "Predicting through Jaimini's Chara Dasha" and "Predicting through Karakamsha and Mandook Dasha". It has been possible for him to produce such researches because he was told by his jyotish guru that what was in parampara (tradition) was much more than what was contained in books of astrology which are translated literally and are without illustrations generally.

His own mother, who was his first jyotish guru, knew many such traditional secrets, parts of which Rao has revealed in his three books “Ups and Downs in Careers”, "Astrology, Destiny and the Wheel of Time" and "Planets and Children". It was the mantra guru of Rao, Swami Paramananda Saraswati, who first asked Rao not to give up astrology as it had to be an integral part of his sadhana. Later a great yogi, Swami Moorkhanandji, prophesied in 1982 that he would be the architect of a great astrological renaissance. Whether that is already fulfilled or not can be gauged from the impressive list of his researches published in his writings.

In the year 2000 when K.N.Rao. was ailing seriously and was unable even to walk, astrology was introduced as a subject of study in modern Indian universities , (it has been taught in Sanskrit institutions for many decades and centuries), it was relentlessly attacked by the pseudo-scientists, pseudo-intellectuals and the media, both print and electronic, carried on a relentless propaganda. A case was filed first against this decision of the University Grants Commission in Madras High Court where it was dismissed on preliminary grounds. The   well known scientist Padmanabhiah filed a similar case in Andhra Pradesh High Court where too it was dismissed on preliminary grounds. Surprisingly, not a single English knowning and speaking astrologers in these two citadels of Hindu orthodoxy even decided to appear as petitioner in person. That speaks volumes for their "love and pride" in the great ancient Hindu astrology. But Padmanabhiah pursued the dismissed case further and appealed to the Supreme Court where the legal luminary, Shanti Bhushan succeeded in getting the case admitted to be heard on merits.  Recovering slowly from his sickness, not yet fit to sit for long hours in a court of law, Rao appealed to astrologers of Delhi and of other centres to appear in person and defend the cause and case of astrology in the Supreme Court. At least twenty of them promised to do so but not one of them came anywhere near the Supreme Court even to hear proceedings of the case when it was being heard for admission ! Later, when it was heard on merits on 4 November 2004, to his consternation, Rao found that he was the only petitioner in person to defend it  and praying to God to give him stamina to defend the case, he not merely defended the case but even won demolishing all the arguments of the famous lawyer, Shanti Bhushan. Read an account of all this with evidences and the court judgement together with the great research Rao has done on the religio-scientific-social legacy of India's composite culture in ASTROLOGY THE SUPER SCIENCE. In this book many of the remarkable predictions given by Rao in mundane astrology are given along with some notable failures about which he had always had the sterling honesty to write as an ideal teacher. The same media, some well known English newspapers and weeklies and the psudo-intellectuals, scientists who never studied astrology but attacked it throwing behind their ignorance the weight of their reputations and, the television, ever referred to the triumph of astrology in the highest court of India !!!   The critics of astrology thus suffered a hattrick of defeats but there are some television channels which still carry on this attack slyly not knowing that they can be sued for contempt of court since the the judgement of the Supreme Court is on the merits of the case. Television channels known as idiot boxes are tabloid in approach,  and  commercial.    If the media has an honest intention of contributing to social causes why does it not take up a fight against fraudulent astrologers who make fortunes in the name of  fraudulent and non existent yogas like KAAL SARPA YOGA  and costly remedial measures through which they cheat people all over India ?  Rao is well known all over the world for some notable achievements, the greatest being as  the founder member of the world's largest school of astrology in the Bharatiya Vidya Bhawan, New Delhi where there are in 2006,  more than nine hundred students and twenty six  teachers on the teaching faculty of the Institute of Astrology.  Not merely is Rao a highly successful teacher but is the teacher of teachers besides being a very rational and scientific astrologer who wants sanity and modernization to a science which otherwise will remain archaic and look like the vestigal remnant of a dogma and not the super science it really is. All the members  of  the  teaching  faculty  of  the Bharatiya Vidya Bhawan are his own former students. He has  encouraged all of them to write books with their original researches and fifteen of them have done it so far.  Single handedly, Rao has encouraged and produced more writers and researchers than any living or dead astrologer. He also edits the Journal of Astrology which is the best astrological three monthly carrying the best researches of the world.  To give to jyotisha through rediscovery and research, Rao has written nearly thirty books some of which have been translated in Russian and Japanese. He has taught astrology to thousands of students in India, USA and Russia over a period of nineteen years now since the founding the Bharatiya Vidya Bhawan. Kartik Poornima 2006.