greetings,

I'd personally suggest you stick with BITS as it is a better college in almost all respects, Since you being a Delhite it may be convenient and tempting to go for IGDTUW, only do so if you are having trouble adjusting at BITS for some reason, regional adjustment, food, language, whatever may be the case, but if you look at this from the perspective of opportunities, student culture, job placements, college repute, the BITS it is.

do not rush it, decide according to your personal interests because they prevail  over anything else.

good luck