Which is the best college in Bangalore for an MBA/PGDM, TAPMI, SIBM-B, or IIM B?

All three institutes you mentioned - TAPMI, SIBM-B, and IIM B are highly reputed for their MBA/PGDM programs in Bangalore. TAPMI and IIM-B are legacy institutions as they were established in 1980 and 1973 respectively while SIBM-B was established in 2008. 

Seems like you are looking for Bangalore colleges only, so I assume you have some constraints regarding shifting to any other city than Bangalore. But if not then you can try and go for some other B-schools in the country. It depends on if you have got calls from all three, in that case go for IIM-B, as it is among the top two or three B-schools in India. 

For further assistance below is a table comparing the three colleges on different aspects;

It is subjective as it all depends on your goals and preferences and also the cutoffs, but if you have got enough cutoffs and got a call from IIM-B then go for it without a doubt.