how host my website on browsers
I use Github, you can use that as well. There is also Netlify.
Its free of cost or not?
You can’t host on a browser. You host on a server.
A simple google search shows some answers.
You can’t host on github in that sense, but there is git pages. As mentioned netlify is popular. You could also drop in an AWS S3 bucket.
It is free. But if you want the domain to be customized, that is something you need to pay for.
I don,t understand what you are saying me