He is a former Vice Chief of the Indian Navy and has the rare distinction of having commanded both the Western & Eastern fleets of the Indian Navy, having served as Commander-in-Chief, South. He has been closely connected with planning the growth of the modern Indian Navy, having served as Director Naval Plans and Assistant Chief of Naval Staff Policy and Plans. Post retirement he has been a member of the National Security Advisory Board and a member of the Government Committee on Defence Expenditure. He also chaired the panel set up by the 11th Finance Commission to recommend defence expenditure for the period 2000-2005.
Admiral Nayyar has been a visiting fellow at the Heritage Foundation and also the US Global Strategy Council. He has lectured extensively in the United States, Japan, the United Kingdom, Germany, Turkey, Iran, Nigeria and the Asia-Pacific
International Relations, the Global Security Affairs, Confidence building measures and Defence Economics.