avilolo

hi. my os version is 10.11.2 el capitan and x code is 7.3.1 I'm needed a gcc compiler plugin for my Xcode for some c programming,i need this compiler because im a stuednt and this is the tool the university use. every gcc is 4.9 or higher will be great. its possible to do it? and what are the real difrences between the compilers?