Hi shewta
you can study directly in IIM after 12th examination but these programs is conducted only in IIM Indore .It will be 3 year program followed by Master program .And student have options  of dropping after 3 year program .The minimum eilgibility criteria is 60% in 10th and 12th These program are Integrated program Management (IPM).So instead of doing b.com work hard get seat in IIM Indore through IPM program.

Hope it will help you out
If you have any doubt you can comment below I am more happy to help you

Good luck

hii swetha

i would like to say the IIMs are mainly for the the management studies and the Phd  programmes whiel they provide only the full time MBA and you cannot do Bcom in IIMas they dont have the course only on the other hand to get the addmission in IIM you should write CAT and get good percentile along with that you should completed an degree as wel

hope this helps