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What you need is a sufficiently concrete goal, that will organise your course of action from now on. I suggest that you try & aim to do a PhD in the US in one of the top 10 (or 20 or 30) universities, in a subfield of physics that you like.
Be warned that the path towards that is not entirely clear. But it is a good organizing goal because it will force you to think, decide & act with some focus instead of treading water & doing aimless things. This focus is extremely valuable. The trouble is that US universities require a four-year undergraduate degree before applying for Ph.D, & most of the Indian universities only offer Bachelor's degrees which are of 3-years. So you can either do Bachelors & Masters & then apply, or you can do engineering, physics or something of the kind from an IIT & then apply. In my case, what I did was to do a B.Tech from IITM in electronics (this was possibly a mistake, but it worked out, fortunately) & then switch over to physics when applying for Ph.D in physics. If you have a good resume, recommendation letters, good GRE scores etc US universities are pretty flexible about switching fields. Here is an answer I wrote before on a loosely related question, maybe that will help.
To the wounded patriots who might get offended by my suggestion to not do Ph.D in India: I don't doubt that India has a competent theoretical physics community at this time, we seem to have attained critical mass in the last few decades, & we do have some first rate physicists here. But competence/excellence etc. are only part of the criterion in deciding where you do your Ph.D. Doing a Ph.D abroad expands your brain like very few other things do, in my experience. So I highly recommend it.
Most importantly, don't make too many inflexible decisions too early (like "I will only study/work in India", "I will/will not work on this topic", etc) before you have had the knowledge & experience & wisdom to decide for yourself. This takes time, so form judgments & act on them, but be willing to change your previous decisions if you find they were wrong, instead of stubbornly sticking to them. Stubbornness is a resource and should be used with extreme caution. For example, I started out thinking that string theory was too speculative but ended up becoming a practitioner over time. As I learned the subject, I slowly realized that I simply wasn't qualified to have the early judgments I had about the subject. Of course, one could say that this is the process of info.