Am I eligible for IIM Ahmedabad with 10th 87.83%, 12th 78.2% and graduation BSc 88%?

You are eligible for IIM Ahmedabad. However, the question is whether you will get a call from IIM A or not. For IIM Ahmedabad, as per the 2021-23 shortlisting criteria, you need to be in the top 80% at each step of academics and CAT. But with your 12th score, you probably won’t be in the 80% as you are from the science stream. So you might not be shortlisted for IIM Ahmedabad.

Your chances of getting into IIM Ahmedabad or any of the BLACKI are quite thin. However, you should consider other top institutions like FMS and MDA that do not take into account past academic performance.

Despite the thin chances try to score 99.7+ in your CAT. Since you are from a non-Engineering background, you won’t face competition from among the engineering graduates. You’ll also get an advantage in the name of academic diversity. Make sure to get some work experience to make your chances of getting into IIM Ahmedabad better. 

Give your CAT all the effort. If not the top IIMs, you will get admission into the best MBA institutions in India.

Past academics are now taken into consideration for the admission into IIMA. I have tabulated the data for past academic criteria below

So from the above table we can infer that for the 10th class you fall in the 13% category which is still hopeful. But for the 12th class you fall in the 3.6% category. So your chances of getting into IIMA are less although not completely impossible. Exceptions are always there.