Dear Aspirant, first be calm and have patience there is nothing to worry about. The basic eligibility to pursue with Aerospace engineering is 10+2 with Science stream. There is no compulsory to give JEE Mains in order to pursue with Aerospace engineering. The eligibility and admission procedure may vary from institute ti institute.

https://www.careers360.com/courses/b-tech-in-aerospace-engineering

(The above link will give you detailed admission, colleges information on Aerospace engineering). If you have any other queries feel free to ask. All The Best!!!