Which specialisation should I opt for in MBA, aviation, hospitality or logistics management? Which is the best college for the same?

Basically, it completely lies on your interest. For Bcom graduate, Finance is a good option to go for. I would suggest you to go for top collegs itself, like IIMA, B, C, L, K, JBIMS, Sydeham, etc. Kindly check the list at below link: https://www.shiksha.com/mba/ranking/top-mba-colleges-in-india/2-2-

All specialisations are good option but recommendations are in following order of precedence: Logistics, Hotel, Hospitality and Aviation for you as a commerce graduate. Refer following link for a list of top MBA B-Schools: https://www.shiksha.com/mba/ranking/top-mba-colleges-in-india/2-2-0-0-0