Hello,

Well you are thinking of very long long path.Going in NASA is not so easy.And by the way , why don't you want to stay in INDIA and serve country by working in ISRO or DRDO , it will be a lot easier.

But first you have to finish your higher studies first. After 12th you can get into IIT or IIST aeronautical branch / aerospace engineering. For which you have to get  good marks in JEE mains and Advanced. 2nd one is better as you will be having a chance to do internships in DRDO , and also get a chance  of getting placed in DRDO. ISRO don't accept placement offer , rather they release vacancies for different posts , on which you can apply.

Still if you want to go to NASA , then you either complete your higher studies from US and then get into NASA , or study in INDIA , then live in US for 5-6 years to get US citizenship , and then apply for full time jobs in NASA.

Thank you