1.) Chinese traditional martial arts. is part of a nationalist movement of Chinese government. china doesn't take into foreign ideas as well.
2.) India are sports mad. if they have one Indian born fighter. they will hook on to the sport. for example
PV Sindhu a badminton player silver medalist in olympics on-court winnings last year totalled $500,000 (£387,000) but endorsements saw Sindhu bring in an extra $8m (£6.2m) in sponsorship in sports-mad India. That works out as a weekly income of $163,000 (£126,000). That is more than earned by Simona Halep, the WTA world number one as of 22 August, and the top seed for the 2018 US Open.
3.) india won 12 medals in wrestling at the commonwealth games. with boxing they won olympic medals and are competitve. even though china are more so however
4.) wrestling amatuer wrestlin already a massive sport in india, its probably a top 5 sport there.
5.) fewer regulations in India