thanks mam for your answer....i have scored high marks in science and maths what is course should want to take mam? can the astronomers work in nasa is tough or easy ?mam..

Praveen rathinam Sugam You should go for plain Bsc Physics and then go for MSc and finally pursue PhD in astronomy. Or you can take up BS-MS integrated course in physics with astronomy major and then go for PhD in the US(as you want to apply for NASA).
It is actually a long way to go before trying for NASA.It is hard no doubt! But you will definitely make it if you are hard working. It will require you to perform really well in your undergraduate program and then finally go abroad for MS in Astronomy and then PhD finally. Then you apply for NASA, they only select you if you have enough research papers published and are passionate about the field. Nothing is impossible. All the best !