Correct answer: Cricket.
The Ranji Trophy is the premier domestic first class cricket championship in India. Teams representing states, union territories, and a few other bodies compete every season for this title. The tournament was started in 1934 and named after the former Indian cricketer Ranjitsinhji, who played for England before India gained Test status. Many players who later represented the Indian national team first proved themselves in Ranji Trophy matches, so the tournament is often called the backbone of Indian cricket.