Whichever of the two you manage to convert will be best for you without any doubt given or taken few factors like location, infrastructure, rankings, and others. On a more serious note, TAPMI has a more heterogeneous and diverse batch of students as compared to BIM, which has a certain number of seats reserved for students of Tamil Nadu.

• Your hostel room-mate and the group-mates of the study group will belong to different geographic locations and having different academic or professional backgrounds. 
• It also has a scenic and modern campus, where peer-to-peer learning is given a lot of importance in addition to classroom learning. 
• Academic rigor is something TAPMI has been historically known for.
• TAPMI was among the first B-schools along with ISB, Hyderabad to get the AACSB accreditation, which puts it in an elite league of AACSB accredited colleges globally.
• There will be a lot more tie-ups with top International AACSB accredited B-schools in the near future, providing for a richer learning experience.

In terms of Placement, both are more or less on par, though of late, TAPMI has seen companies from various sectors (including e-Commerce) placing students with packages crossing the 7-digit mark on a regular basis.

In the end, everything boils down to you opting for which college. After all, after graduation investing one or two more years is quite worthy if it is from a good college.