How to start??

My aim is to research in engineering (mainly astrophysics) hence I was looking into IVY league institutes as they have a higher rank in research. I found out now that the fees is too high and no financial aid is given to international students in MIT.
On the other hand, I am also preparing for JEE(Main+Advanced) where IITs have way less fees.
My question is that which is better and more worth to take prepare for, SAT or JEE ?