If your final aim is to crack CAT, then you have already decided that you want to do an MBA. And if management is your ultimate aim then branch is not exactly a matter of consideration for you. On the other hand, a college with campus placements is always a better choice, since cracking CAT also has an element of luck.

So, even if you crack it in a few attempts, and you are employed, then the pressure on you would come down drastically. And in the long run a college with good placements will have a better alumni network and that would further help your professional growth in the long run.