Been watching a lot of the tournaments which I believe are held in japan and there's only a handful of fighters that are used and majority are them are female characters.
Hmm which tournaments? from the those I've been watching for Tekken 7 FR (the latest arcade version), there's quite an even mix between male and female characters and good variety too. Same with recent tournaments I've watched in the US/EU.
As with most fighting games there'll probably be a handful of fighters that are rarely seen, but I expect variety will hold well as the game matures and balance patches are released.
in street fighter tournaments you will see the same 2-3 characters always being used.
Nah, in SFV at least (and even late-SFIV) there's a good variety of characters played at major tournaments.
It's not uncommon to have all top 8 players playing different characters in SFV - there was a major this weekend and there were 7 different characters played in the top 8 for example.
If you consider the top 64, or even top 32 players at a major tournament, you'll probably see just about every character being played if not all.