Hello Akshat,
IIM's are the top-notch colleges in India, so obviously to getting admission in it not an easy task.
Also, there are a number of factors required to get admission and not just 12th marks. You also need to have B.com with at least 50% marks, with a very good percentile in CAT ( minimum 90%), plus work experience along with many co-curricular activities. 
So you need to look into all these factors and decide accordingly your chances.

Hope it helps,
Good Luck.!