Honestly, anyone with a decent profile can pursue MBA from IIM Ahmedabad. The question is how well you can score in your CAT. Anything below 96 is not accepted.
Another tip that will help you get selected for MBA from IIM Ahmedabad is to make good use of your Bachelor years. You can:
Study Economics and Business alongside BSc
Participate in National & University level Business Case Study Competitions
Enhance your English speaking skills
To prepare for the interviews, read newspapers, articles and essays on current economic issues. Lastly, answer all the questions confidently.