Hello Rahul,
B.Tech (Aerospace Engineering) is a 4 year duration course. Eligibility criteria for admission to the course is student must have minimum 60% marks in PCM. College is good in terms of facilities like infrastructure, campus life, etc.
Decent placements are offered at the Mumbai campus but majorly IT companies visit the campus for recruitment.
Go through the links below for details-

http://www.amity.edu/mumbai/btech-aerospace-engineering

http://www.amity.edu/mumbai/about-placement

Good Luck!