Roy received a Bachelor of Science degree in 1982 and a Master of Science degree in Inorganic Chemistry in 1984 from Visva-Bharati University. Five years later he earned his Doctor of Philosophy degree in Science from Jadavpur University.
Roy began his career as a researcher of Inorganic Chemistry Department at Indian Association for the Cultivation of Science in 1987 and held it for three years. Then in 1991, he took a position of a research associate of Nanostructured Materials Division at the Central Glass and Ceramics Research Institute. The same year he was a senior dy general manager at Bharat Heavy Electricals Limited.
Also in 1993, Sukumar was appointed a visiting scientist at New York State College of Ceramics of Alfred University. Two years later he served as a guest scientist at Max Planck Institute for Intelligent Systems and held it until 2004. Since 2015 Roy has been a senior dy general manager and corporate R&D at Ceramic Technological Institute of Bharat Heavy Electricals Limited.
Roy is a member of Indian Thermal Analysis Society and Indian Association of Cultivation Science.
On February 20, 1987 Sukumar Roy married Lina Gangopadhyay. They have a child.