Top Physics Colleges in India
“Best” is pretty subjective. One means to determine the “best” could be to look up college rankings. But there is a problem with this as well. Because colleges are typically ranked for their degree programs (like Physics, Chemistry, Computer Science etc.), but not for specific courses.
You could for instance look up QS:
I also found this list of top quantum physics programs, but this is at the graduate level:
The same course offered by a college may vary a great deal from year to year (as the instructors change and teaching methods evolve).
So, it is really hard to pinpoint a college which offers the “best” quantum mechanics course. However, I can tell you that in India, the Physics courses offered at the IISc, IISERs, IITs and BITS are pretty good.
Fortunately, we have online access to the quantum mechanics courses offered by numerous colleges. Thus, no matter what college you end up in, you would always have the chance to explore the teaching at other places.