First choose science for 11th and 12th, and then check for yourself if you are still interested. And then you might want to go for B.Sc degree in Physics, and then M.Sc in the field that you want (astrophysics/quantum mechanics/cosmology) and after that if you are still inclined, you might want to try PhD in any of the subjects. But my advice right now would be, focus on short term goals, instead of going so long-term and object oriented. Gathering information is a great quality, I like that you're interested in these topics already. Hope you make a great physicist one day!

Hi Pranav,

If you are interested in the topics you have listed then I suggest first you should start taking parts in Olympiads. There are various national and international Olympiads for students interested in theoretical physics. Then after that, you must choose PCM(Physics, Chemistry, Mathematics and Computer Science) as your subjects in +2. Try to score at least 95% in your +2. It is true that +2 marks do not matter in the long run but they will surely help you in giving some advantage over the other students as you can easily get admission in one of the top colleges offering BSc in Physics and this is the best opportunity for you to pursue a career in theoretical physics.

Then you must try for foreign Universities for Masters in Physics there you will find many people equally enthusiastic about physics as you are.

Try to do your Bachelor from India and then too from some top college like St. Stephens Delhi. For that, you needed a good percentage in 12th. Also, give JEE ADVANCE and try for IIT Kanpur BSc course in Physics.

Hope this helps.

Here are some additional links for you:- https://university.careers360.com/articles/du-cutoff
https://university.careers360.com/articles/du-colleges
https://university.careers360.com/articles/du-colleges
https://engineering.careers360.com/exams/jee-advanced
https://jeeadv.ac.in/
https://studyabroad.careers360.com/tags/ms-abroad

All the best. Thank You.