Mentor Graphics Licensing (MSL) is a 32-bit application and requires the 32-bit libraries on 64-bit Linux systems as well as the Linux Standard Base package, which may not be loaded by default on RedHat 6.
The following command will install the required 32-bit compatibility package:
yum install glibc.i686
On RedHat 6, load the LSB package with the following command:
yum install redhat-lsb.i686