See, since you want to study purely B.Sc in physics honors, then the best colleges for you would be in Delhi University, in the country.

Of course, colleges like Presidency in Kolkata and Xavier's in Mumbai do offer good courses, DU is the best of them all.

However, for DU, you will need to calculate your best of 4 score since the admission is class 12 merit-based. You have 3 good core subjects already included, you only need a language subject to calculate your best of 4. If your score is above 90 percent (Gen), then you have a good chance of landing a seat in Delhi University.

Good luck!