M.Tech

You shall refer O. P. Tandan for physical chemistry, Arihant for organic chemistry, Concise Inorganic Chemistry by J. D. Lee and Objective NCERT by MTG.

You have not mentioned your reasons of drop out. If drop out was because of poor performance then no Engineering college will give you admission. If your Performance was good, you may seek transfer to new college.

Hello Arpan,
Placements in IIT's or IISc after graduation or PG is normally with well-known companies and as a result average package offered is about 8-10 LPA.

Hello,
This is quite not possible to say, surely that you can earn 1 lakh per month as salary after completing your M.Tech as there are a big crowd are waiting for engineer so it's tough to get this much salary. Yes, it's possible if you have done your M.Tech from reputed college and with good marks.

CSE is better as it provides good scope and salary packages than mechanical engineering.

Yes, there are various colleges in which you can apply for M.Tech without GATE qualification or something like that. I can give you some names like Vivekananda Global University, JECRC University, etc. from Jaipur.