Least cutoff you should aim (above) is 85 percentile. There are some other factors too which gives you a weight age along with your CAT overall score like your academic records, work experience, your extra curricular activities & your overall profile.

Profile means your participation in extra curicular activities, your awards/certifications if any, your particpations, your initiatives, organising events etc. Skills and interests you have and all of these.

So the more of it the more chances they take you.

Hope this helps.