wrong file, thats the entire base for X, not what you need, im guessing you only need the X devlopment package, which isnt very big, its just a set of apps and libraries that allows other programs to use X more effectively.
Im not sure what redhat is gonna call it, but it should be on your install disk, mount it, cd into it, and have a look in whatever section it keeps the files for X, find that development package and install it, occasionally some distro's dont install it by default.