Hey Prakhar,

Firstly, you must clear the CAT examination. Once you have cleared the exam then you take these points under consideration.

IIM-A is one of the best IIMs in India with very high requirements. You must be aware of the point system and these differs for all the IIMs. Ahmedabad being the best, keeps it high usually. With 85% in grads you'll score 8 pointer and in 12th you'll get a 10 pointer. It might be enough as an academic score but with no work experience it might be a little tricky.

It's adviced to keep your CV heavy so that nobody can ignore it. Still don't lose hope, go for it.

Good luck!