You can technically install it on there. The difference between any linux distribution is the package management system and init scripts, and a few other misc things.
Generally it's a good idea to stick with what packages are provided by the official sources in the package management system. But technically you can put anything you want on there.
There is nothing stopping you from downloading and building PHP yourself. You could even bundle it up in a nice little RPM if you like. Problem is, if you ever want/need to upgrade, you'll have to build it again. Quite the pain. not as simple as yum upgrade anymore.