M.Tech Computer Science and Engineering

It will be good if you are joining UPES for M.Tech because you will be placed in good companies after the completion of your course. There are many companies which visit UPES and if you are a bright student then you will be placed without any difficulty. So you need not to worry about it.

Both are different of fields. You should go in which you have pursued B.Tech. You should do M.Tech with the same branch that will enhance your knowledge in same field and really help you out for the good future.

I'll refer you to join B.Tech CSE rather than integrated 5 year course because if you change your mind in 4th year of your graduation seeing that time scenario then it will be better for you to join MBA or by qualifying GATE you can join any of the PSU because joining integrated course is only beneficial if you have clear goal to join in research or be a professor in any college.

Yes, you are eligible. For more details, check the link below:
https://www.shiksha.com/arts-fine-visual-performing/course/m-a-meerut-college-272301

Go for MANIT CSE or B.Tech CSE programme instead of any dual degree at other institutions.

It doesn't matter on the course. It matters on your ability, how talented you are, your communication skills, your technical skills.
Both are good.
From my suggestion, go for B.Tech+M.Tech.

https://cbsenet.nic.in/CMS/Public/View.aspx?page=80
Yes, but be sure that your percentage is at least of 55% in your Master's degree. Please check on above link you will get the details. It is official site also.