Hey there

There is no aeronautical engineering in IIT Delhi though there is aerospace engineering degree course in IIT Bombay and the admission is through JEE advanced not through JEE main. For admission in IIT Bombay aerospace engineering your rank must be below 2000. There are other iits which provides aerospace engineering also.

Check colleges provide aerospace engineering in India.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://engineering.careers360.com/colleges/list-of-aerospace-engineering-colleges-in-india&ved=2ahUKEwiB9sjoyrzkAhUMto8KHX6wCqYQFjACegQIDhAd&usg=AOvVaw1aH-H8XDqDyazzm5pTe675

Good luck