The cutoff percentile for almost all the IIMS usually go above 90 percentile but IIM Ahmedbaad has remained less than that since 2016. So it's average cutoff is usually around 82-85 percentile. At the same time your AR Score matters which includes your 10th / 12th marks, work experience, etc. As well..

For getting AR score of a particular candidate ratings of , 'A' and 'B' and 'C' will be computed based on her/his percentage of marks obtained in 10th standard, 12th standard, and bachelor's degree examinations respectively.

A grade institutes consider your 10th and 12th marks and include these marks in their selection criteria, which simply means if hypothetically, Candidate A and B score 90 percentile in CAT, And candidate A has scored higher marks in school than B did, there are high chances that candidate A will get an edge over B.

Obviously, there are other factors like Graduation marks, work experience but the 10th and 12th are important to some extent.

Thank-you.