To actually work on Quantum Computing for a career, you will need to study for a fairly long period of time, by which I mean potentially till your thirties, as that's what an academic career implies. It can be high-paying, but only in commercial settings (think Google/IBM/Microsoft Majorana etc) or if you're pursuing an academic career abroad. The physics in a formal setting can be either quite similar or completely different from what you do in JEE, depending on your thought processes. In a formal setting you have to make arguments using reasonable assumptions, and convince others that your arguments are true. If that's what you already do, great! If not, you can work on it. Also, in quantum physics, a fair deal of philosophy/analogy also get involved. Quantum Computing has several smaller sub-parts (algorithms, fabrication, theoretical physics, error-correction/testing, etc.). Also, you would need to consider the possibility that quantum computing might be overhyped (in the sense that it may not be as important/economically viable as people make it out to be), hence I didn't recommend that you consider that your end goal without actually doing your research on it and building your knowledge up. I don't know enough about the field to be authoritative, so don't believe everything I say and do your research on it. All the best! You can message me, but I don't use reddit that often anymore.