How do we host a tournament??

We?

Perhaps you mean your club. 

https://www.chess.com/club/the-indian-club

I see you are the only member.

That's going to make it tough to hold a tournament.

But you can set one up, I think:

https://support.chess.com/article/1205-how-can-i-create-a-live-blitz-bullet-rapid-tournament

It will be cancelled unless you get enough members.

I guess I would try to get a bunch of new members before you set up the tournament.

Thank You!!

how to join a tournament?

how to join a online free tournament in india on chess.com?

What tournament? Do you at least have the name? Or what club or group is organizing it?

want to host a tournament

@Htade was not the original poster. Neither was @Kartik541.

Things can get confused when multiple people join existing threads and ask different questions. They should start new threads to help avoid causing confusion.

@Satwixx started the thread. He has a club and wants to host a tournament but he has no members.