there is nothing like pass marks is allotted to have in cat exam. cutoff marks for different institute decided separately and it changes every year, the more of marks you will get, your chances to get in top institute will increase proportionally. hope you may understand.
CAT Pathfinder - IIM & Non-IIM MBA Call Predictor
Know Your Calling Chances from IIMs & other Top MBA Colleges, Eligibility & Cut-offs