Hello Rasagna...The minimum percentile that is required for any IIMs is 90 for general category and for obc, 75 percentile or above 75 percentile is required in any IIMs...so if you belongs to obc category then you must have minimum 75 percentile in CAT exam...but as you told you have got 45 percentile,it is hard to get a chance on any IIMs...but keep trying...If there is a will there is way...so best of luck for future.