We tried logging into TAC console with admin@company.com/admin but it did not work, we even changed the password to 'admin' and still were unable to login. We are not sure how to resolve this issue so if you have any idea on how to fix this please let us know!
Note: We validated that all LDAP connection is correct.
I think we need more information here. I presume you are trying to log in to TAC when you get this. Has this worked in the past, but has suddenly stopped working? If so, when did it last work and has anything changed since? You say that you are running QA on v6.2. This is way beyond end of life. I suspect that an upgrade would be the best course of action here.