There's a file /etc/inittab which tells init (the ultimate parent of all processes on a Linux system) what processes to start when the system boots up. The "respawning" error message means that init tried to launch one of these processes and failed. You're seeing it six times, with six different ID numbers (the numbers correspond to the numbers in the inittab) so it's almost certainly the /sbin/mingetty processes that handle terminal logins that are broken.
Why they're broken, I can't say. The executable could be deleted, or moved or renamed, or overwritten; a disk error could have wiped it out; the /etc/inittab could be configured to work with /sbin/mingetty, but mingetty isn't installed; the /dev/ttyXXX files are missing, or have the wrong permissions; there are all kinds of reasons.
Your first order of business is to be able to get on the system again. What I would do would be to boot with the RedHat recovery disk, mount the existing disk in read-write mode, then edit /etc/inittab so that the getty lines look like
1:2345:respawn:/bin/sh
2:2345:respawn:/bin/sh
...
Then when you reboot,
you should just get a root prompt, with no login.
From there, you have to figure out why /sbin/mingetty can't launch. Good luck.