Both the colleges are equivalently comparable. BIMTECH wins hands down owing to its location and the Birla brand value. Many of my friends have graduated from BIMTECH, they suggested BIMTECH Core because the exposure you will get at NCR will be much better than at Nagpur. 

Here’s a brief comparison of both the colleges. 

MBA is not about the syllabus, Its about how much you learn and get exposed to. Hence, I would recommend you speak with current students of IMT as well as BIMTECH, even try to visit both the campuses if possible, and then make a decision.