In my opinion you should go for medical .college Kolkata/ NRS Kolkata over other AIIMS colleges. This is because of the patient flow in these hospitals. The new AIIMS lack in this very important aspect since they are still relatively new. However if you wish to get the AIIMS tag and a theoretical education of AIIMS then go for it. Bhopal, Jodhpur and Bhubaneswar have come up well in the past few years.