Selection procedure
Initial shortlist for FMS happens basis CAT percentile. No previous acads or work ex are taken into account during the shortlist though they play a role in the final selection post Extempore and PI. (for eg, if two candidates are tied at the same score post these rounds, the one with better acads might make it through.)
For CAT score cutoffs, check what been the cutoffs set by the institute in the last couple of years and that shall give you an indication of the %ile range required for getting the shortlist across categories.