RedHat RHEL6.4 is really not a free operating system
you MUST buy the required support contract to install updates and most anything else .
There is a free rebuild called CentOS 6.4
but it's target user IS the redhat system admin .Or someone with a lot of red hat experience .
There is a very steep learning curve .
As to Backtrack 5
It is based on the now unsupported ubuntu10
and bt5r3 is basically not really supported any longer.
they released a NEW operating system
but it is NOT intended for the "new to linux user"
it is targeted at the Professional security testers and network admins
you really DO need to be able to write your own scripts to use that operating system
and you DO NEED a very good working knowledge of networks ( wired and wireless )