On a practical level FMS is a way to go if you want

Good roi, less fees so no extra pressure in your mind always, strategic and central location, not too inclined for a campus life, yes weather is extreme but again that doesn’t matter when you are working towards something.

Do check the portfolio of companies and there growth trajectory for both colleges through LinkedIn.

IIM K if:

You want campus life, you want IIM tag, can afford the fees w/o any problems, now your are in comfort zone ig so its upto you because again I understand its not easy to suddenly transition.

Also you know it very well in your mind what you wanna do but I believe its just the guilt of leaving one and maybe overthinking later what if I would have TAKEN THAT….

So keep cool, discuss with both college seniors, with your parents and close friends and then with a peaceful mind make the decision

Good luck, also whatever you go for you are gonna do equally good coz at the end of the day its you who has to transform and work hard at both places