Engineer

Hello Asif Raza,
It depends on you, but I will suggest you should opt for mechanical engineering because it is an evergreen field. Aeronautical also has a good scope, but it doesn't have much demand as compared to mechanical engineering. Mechanical engineering has more scope for future. In future, you can move opt for Masters in aeronautical engineering.

Good option, it is based on total industrial applications, designing of pipes, etc. According to me, you should opt for chemical engineering. After completing you chemical engineering you can work as a process engineer, piping engineer, technical engineer, production engineer, etc.

You can refer to the links mentioned below:
http://www.payscale.com/research/IN/Job=Aeronautical_Engineer/Salary
http://www.payscale.com/research/IN/Job=Mechanical_Engineer/Salary

Hello,
Yes, you can get a government job after completing your engineering.
You can get a job in banking Field or in Indian Railways.
There are too many posts available for engineers.
You can apply for Railway RRB JE & SSE Exams or IBPS Bank Exams.
Click here for railway exams preparation - http://entranceexaminformation.blogspot.com/2016/06/railway-rrb-exams-are-you-prepared-for.html
I hope it will help you.
Best of luck.

You may refer to following link for information of all engineering entrance examinations: https://www.shiksha.com/engineering/exam

Yes, you can work as a facilities engineer after mechanical engineering. Your salary will be decided on the basis of your company and your abilities. It could be around 15000 per month if you are a fresher, otherwise its range can not be defined exactly.