Indian Institute of Technology, IIT Bombay

For admission into IITs, JEE Advanced score is taken into consideration. JEE Mains score is taken into consideration for qualifying for Advanced examination. If you have cleared the cutoff, then you can appear the advanced.

It can be anyone of the top tech companies in the United States.
Google,Microsoft, Facebook, LinkedIn and many more.
Check out Glassdoor, it should give you a pretty good idea.
www.glassdoor.com

Currently there is no provision of lateral entry in BTech for Diploma holders in Mechanical Engineering in IITs. If you have PCM at +2 stage you can appear for JEE to seek admission in IIT.

Since the packages are not officially revealed so the information is not sure but the average package goes around 8 Lacs P.A.

I would suggest you join a good coaching classes after 10th exam and do a 2 year course for JEE advanced.

For opting IIT Bombay you need to clear JEE Advanced and for giving JEE-advanced you need to clear the cutoff. The cutoff was 114/360 in 2014 , 105/360 in 2015 and 100/360 in 2016 also you must have more than 75% in 12th Board all these cutoffs are for General category.

After completing B.tech in aerospace either you can opt a core or non core job via placement cell. Or you can you can convert to B.tech+M.tech (5 year) here from IIT Bombay, or you can go for MS from Foreign Institute. These are the options which most of the students choose. Also you can start your own Startup if interested.

Packages are not publically revealed hence i'm not sure.