After a B.Tech from an IIT, should one go for an MBA from IIT Bombay / Delhi or from newer IIMs like Kozhikode or Ranchi?

The answer to your question is objectively based solely on your inclinations. IITs might offer a better ROI than IIMs. But had I been in your place I would have gone for the newer IIMs like Kozhikode or IIM Ranchi which is one of the fastest-growing IIMs. The reasons for taking this decision would have been

• Better opportunities in finance, marketing, and consulting domains.
• Better placement opportunities 
• Better industry exposure
• The prestige of being a part of the IIM alumni network
• The IIM tag 

All these points make IIM a more tempting choice. Yet if you are tight on budget and just want to go for the Operations domain IIT will do fine for you.