RH6? That's very very old. Anyway, assuming you have to stick with it, did you at any time create a password for root? If so, do ctrl+alt+F<
n> where
n is one of your function keys until you get to a console login. Login as root and use adduser or useradd to add a normal user.
Definitely switch to a more recent distro when you have tyhe opportunity to do so - RH6 went end of life some years ago and there are no recent security updates or patches.
And welcome to LQ