Here at work, the system admins were required to install PHP and php-mcrypt on RHEL6.. The admins faced an issue saying that php-mcrypt does not exist on RHN repository. So, I get a call asking for my help.
Fedora Repository had the PHP mcrypt extension and library: Link to Fedora Repository
Then run the command:
yum localinstall libmcrypt-2-1.5.8-9.el6.x86_64.rpm php-mcrypt-5-1.3.3-1.el6.x86_64.rpm
rpm -Uvh libmcrypt-2-1.5.8-9.el6.x86_64.rpm php-mcrypt-5-1.3.3-1.el6.x86_64.rpm
I’d prefer yum to resolve and download any dependency requirement. If using RPM fails due to dependency requirements, you will have to download them manually.