Son of former Railways player Jai Prakash Passi, 21-year-old Sumit took to the game at a very young age as he looked to emulate his father who fully supported his decision to be a footballer. He started his footballing education with Chandigarh Football Academy and in 2007 captained the Chandigarh football team at the under-14 level during the 53rd National School Games. He made his professional debut on February 2, 2013 by coming on as a 77th-minute substitute for the Pailan Arrows. The following season saw him move to I-League outfit Sporting Clube de Goa. Passi made his international bow for India during their AFC Asian Cup qualifiers and scored his first goal for the country in a 6-1 thumping of Laos on June 7, 2016.