Madras Institute of Technology is under Anna University. These two aren’t separate. If you want good job profiles with cushy salary packages, after completing your degree, MIT isn’t a good option. Not many core companies visit the campus drive for recruitment. Although placements in the non-core sector are good. MIT offers good academics and you can benefit from the institute if you are aiming to pursue higher studies. The course fee is nominal. The course costs around INR 1.58 lakhs.
SRM is a good option if infrastructure is your priority. Although the university fees are a little higher.
My sister studies Aerospace Engineering at MIT and I must tell you that Madras Institute of Technology is one of the four campuses of Anna University. They are not different. It ranks #8 on the NIRF ranking portal, but its current placement rate for Aerospace Engineering is not that great. You may have found your reasons to join this program, however as a word of advice, here's what you need to consider before joining -
Similarly, don't join aerospace engineering because your teacher asked you to, or you have dreams of seeing rockets and other aerial transports, or if you wish to become a pilot or want to join ISRO/NASA for that matter. You must know that only 50% PSUs employ mechanical engineers through GATE, but only DRDO employs Aerospace Engineers with 5 vacancies in a year. So research with intent.