Do i want to write jee exam to become scientist

Hello alifya
I understood your query like this that "you want to know whether you need to write jee to become a aeronautical scientist"
See in my opiNion if you get into nits or iits where there is a aeronautical engineering branch then it would be easy for you to do research.
Many of our nits and iits have direct collaboration with the isro they send interns and also appoint jrf's from these prestigious institutes .
As these institutes consists of very highly experienced faculty you can do your research with good scope and can gain good skills.
There may be many other ways to get in but this must be the easiest and also best way to get into the isro with some great knowledge.
Hope my answer helps you.
All the best....