I am currently using Firefox but i want to use TOR browser to login Bitcointalk. Is it safe to use TOR browser as i heard it is a dark web browser where hackers can hack our credentials and information ?
Using TOR browser to browse bitcointalk won't affect you at any stage, you might have issues if you try to sign up with TOR browser due to evil points.
TOR is not darkweb, it's just a browser which keeps changing its IP location but if you want to enter into darkweb you need to have onion URLs for the site you wanted to visit.