To get into IIM Ahmedabad's MBA Program, you are required to score between 98-100 percentile in the CAT examination. Even if your CAT score is 99, it can not be guranteed that you will be admitted. Your school marks are decent and should be beneficial in the admission process. Make sure your college grades are also great and your extra curricular activities are good enough. After this, all you have to do is ace the interview and GD.