I've done my MBA from Quantum University, so I can tell you how it actually works.
If you have a CAT score around 60 percentile, that's usually enough to get considered. But the good thing is — admission doesn't depend only on CAT. Even if you don't have CAT, you can still get in because Quantum has its own selection process, which includes a personal interview and a simple written/aptitude round.
They focus more on your interest, communication, and clarity about why you want to do an MBA rather than just the exam score. So don't stress too much about hitting crazy percentiles — just prepare well for the PI and you'll be fine.