UPES

UPES has a good placement record of mechatronics branch and students from UPES get offer from good companies like:
Birla Soft Technologies,
IBM,
Infosys,
Aveva Softwares,
Weatherford Drillng,
Caterpiller,
Cummins,
Escort Ltd,
HERE Maps,
JK Tyres, etcetera.
Around INR 4.5 LPA is the average package that a campus placed mechatronics student gets.

Not all the branches in UPES are fruitful, so you should ask the question relevant to a specific branch. Then only one can answer if it is worth taking or not.

You get to do the internship from the college itself. You can grab it in GE (Oil and Gas).
Industrial tour in Refinery, LNG Terminal & an onshore gas processing plant.
The placements of both the branches are excellent since both are the core branches of UPES.
You can check UPES Website for the reviews of these branches written by the alumni.

So you have two universities to compare for MBA-HR.
Let us talk about Amity University:
Pros:
Good Course Curriculum
Good Infrastructure
Cons
Placements: This is disappointing because 4 out of 20 students gets placed with an average package of 3.5 LPA. The other has no option left than picking an off-campus job of 15k-20k.
UPES
Pros:
Excellent Course Curriculum and Infrastructure
Placements of this branch in UPES has always been trendsetting.
Cons:
The university just lags behind in terms of high fees.

Please refer this official FAQ for your every query about the college recognition.
http://www.upes.ac.in/FAQs

No, UPES doesn't have any specified course for mass communication neither in Undergraduate nor in Postgraduate. However, that is taught throughout in each course offered.

Yes, from wherever you belong, you can definitely give the Common Entrance Test.
There are various CET exams like JEE Mains, MUOET, MH-CET etc. Please tell which exam you want to give so that we can elaborate about it.

It is fair if you can opt for career in oil and gas in MBA as many of the students from B.Tech branches opt for MBA in oil and gas. Apart from all the placements, oil and gas is highest placing branch in our college. As 4-5 days ago one of our students from the same batch got a placement of 19 LPA. So doing MBA from oil and gas department is good enough.

There are lot of opportunities provided with various companies exposure.

It is not tough. Just do your best.