A huge thnx to all of you who commented. 
Ohk so I’ll be completing my BSc (Physics) from DU, which is 3yrs here. Then, I’ll apply for PhD in US.
I’m already in top 1 percentile of the country, but even then, I’ll be working hard to get the topmost grades in college, along with acing the GRE and doing lot of research/internship work.
Anything besides this to boost my chances to get into MIT, CalTech, UC-B or Stanford for PhD ?