Anyone getting admission to any IIT should not consider NITs then. It’s true that the old IITs have better infrastructure and brand value than tier-2 IITs but these new IITs are still in their development stage and haven’t reached their conclusion. Considering their huge growth over the past decade, they will reach new heights in the future
The new IITs provide better opportunities and freedom to students as the foundation of the college isn’t very strong so they build it alongside. The students grow and develop their personalities along with the growing institute. There is no compromise in the quality of education as the faculty is recruited after tremendous filtering.
The branch is more important than the college so don’t choose a less preferred branch in an old IIT just for the brand value rather go for the branch of your choice in a new IIT.
As for Physics, it requires genuine commitment and interest. Go for it only if you are certain of a career in it as the options in this branch are limited in contrast to Electrical Engineering. That being said, IIT Ropar is one of the best second-generation IITs, and its curriculum is very flexible and the location is also great. So my final recommendation would be to go for IIT Ropar Electrical.