Indian Institute of Technology, IIT Bombay

The admission in IIT Mumbai are based on ranks obtained in JEE Advanced. Last year's closing rank in B.Tech CSE at IIT-B for neutral gender general category was 63.

For every college KCET rank is required, So better to write KCET and however with respect to rank you can get the college. Government Colleges are also there.

The last year's closing rank at IIT-B in Chemical Engineering in General Neutral gender and PWD category was 123, which is equal (approximately) to 265 Marks.

IIT Bombay, IIT Kharagpur and IIST Trivandrum are offering B.Tech in aerospace engineering course. The admission in IITs and IIST are based on ranks obtained in JEE Advanced conducted among the JEE Mains qualifiers. Hence, first you have to qualify the JEE Main exam and then appear in JEE Advanced exam and obtained the minimum ranks as mentioned below:
IIT-B : 2082
IIT K : 3822
IIST : 11215
The best approach is to join any JEE preparation coaching institutes. Because more than 90% of students get selected in IITs are coming from the coaching centers.

GATE score (normalized) of admitted students in M.Tech Chemical Engineering at IIT Bombay in asked category was 568. So, you can estimate here yourself.
All the best