Install NVIDIA driver to RHEL6

$ setsebool -P allow_execstack on
$ nano /etc/modprobe.d/nvidia-installer-disable-nouveau.conf
and put in
blacklist nouveau
options nouveau modeset=0
$ nano /boot/grub/grub.conf
and append
nomodeset rdblacklist=nouveau
to the kernel line
$ nano /etc/inittab
change
id:5:initdefault:
to
id:3:initdefault:
$ shutdown -r now

After reboot:

$ sh NVIDIA-Linux-x86_64-xxx.xx.xx.run

It will install normally.

$ nano /etc/inittab
change
id:3:initdefault:
to
id:5:initdefault:
$ shutdown -r now