You should be able to just apply the "Out Color" output of the normal map texture to the "Normal Camera" input of the material, like step 14 of jeffro's tut, and it should render, at least in maya software renderer. Not sure if that's how you render normal maps in mental ray, I would assume it's the same.
Mop thanks, that is a great tutorial but the problem is it only shows how to render them in real time in the viewport, I was wondering if there is a way to render the scene and have them show up.
ndcv I tried that one tonight but it seemed to not work at all in maya software render and in mental ray it seemed to be working to some degree but looks different than I expected.
hrm... did you use maya to generate the normal maps, or some other program like Orb or ZBrush? To be honest I don't have maya 6, but I had normal maps rendering in maya 5 at some point and I THOUGHT I just hooked it up to the normal camera... I will check into this...