During his college days at King's College, Cambridge, Roy received three honours from the institution; Powel Prize for the best student in natural sciences (1964), senior scholarship (1964) and honorary scholarship (1965). The Council of Scientific and Industrial Research awarded him the Shanti Swarup Bhatnagar Prize, one of the highest Indian science awards in 1987. The Indian Academy of Sciences elected him as a fellow in 1989 and he became a fellow of the Indian National Science Academy in 1992. Two years later, INSA selected him for the exchange fellowship between the academy of the Royal Society and the American Physical Society elected him as a fellow in 1995. He delivered the Meghnad Saha award oration of the Indian Association for the Cultivation of Science in 1997 and received the elected fellowship of the National Academy of Sciences, India in 2001.