you do NOT put new software on that old rh install
you BUY RHEL 6.2
see pricing guide
red hat did a name change back in 2002
RH7.2 changed to RHEL 2.1
so RH6 predates that
the kernel version " 2.4.21-4" is very dead
2.6 ans 3.2 are the current
However from your kernel
it looks like this is RHEL3 ( also past it's end of life ) and it is NOT supported any longer
Red Hat Enterprise Linux 3 (Taroon), 2003-10-22. Uses Linux 2.4.21
so if you MUST use this very old and not supported ( think of it as running " windows 98 "
then DO NOT connect this to the internet
Unless you WANT
the server compromised and taken over by a bot herder .