I am assuming you are from general category. A lot depends on your profile. Assuming you have a decent overall profile(85%+ throughout), you will be needing above 99.5 percentile to get a call for the next round.

All the best!

In order to take admission in IIM A you need to appear for CAT entrance exam. The candidates are short-listed for Academic Writing Test (AWT) and Personal Interview (PI) from among the candidates who have a valid CAT score. You should have more than 99 perecntile in the entrance exam & overall a good profile to get admission there.

Good Luck!