Hello Ma'am.

Firstly... have a real passion for it. It isn't an easy job to become a scientist in this very vast and deep field. And the second most important thing, have patience. If you are doing research, you should know how to keep it cool. Try to avoid negative people saying that 'research has no future'. It has a lot of scopes even in India and abroad. If you have real passion, you will see your job to be a very interesting life! It won't just be a 9-5  messy job...

Coming to the path: I am assuming that you have completed your 10th-grade board exams. Getting into science stream is a very obvious answer. You can appear for good exams like KVPY in 11th and 12th. Cracking this exam will let you apply for IISc, a best research institute in the country. I highly recommend you to target it. Also, you can appear for JEE and NEST and even BIT-SAT. Your prime motto should be to get into the institutes like IITs, IISERs, BITS Pilani and NISER for integrated BS-MS course. 

If you don't get it... no worries. You can still pursue B.sc from other good colleges. For this field, it's very important how well focused you are on research. You can then appear for IIT-JAM to get selected into IISc or IITs for Masters degree.

Co-curricular: Stay focused on your career, that's it. You can watch online lectures of many professors from awesome Universities in the world. Keep updating yourself. Try to go through as many research papers as possible in your undergraduate studies. Always try to be curious. Have your social existence as well; by this I mean try attending seminars and lectures of famous scientists, participate in Science talks, etc. 

In the end, two things matter: Your knowledge and your ability to deliver that knowledge.