Hello.
If we have a concluded comparison then I would say IIM Kolkata is quite better than IIM Bangalore  there might be various reasons but it may vary according to you what you actually want to have from these institutes if you have already selected in any of the one then you can go with the provided link and compare in detail and can select better one:
https://www.careers360.com/compare-colleges
if you haven't selected then you can go with the provided link and can predict the college according to your score:

Best of luck.

Birla Institute of Technology, Mesra (BIT Mesra)

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IIM Bangalore

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IIM Calcutta

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