Hi Aspirant,
My first recommendation would be Petroleum Engineering since it is the core branch of UPES and hence all the facilities and all things are to be provided by the institute in an excellent manner to petroleum students than to any other branch. My second recommendation would be Computer Science with specialization in Cyber Security since there is a lot of future scopes in computer science. Also for getting a good branch don't miss out to check which branch has higher placements, refer the link below to check so
https://www.google.com/amp/s/university.careers360.com/articles/upes-placements/amp
Hope this helps.
Thank you!

Dear Atharv,

In UPSES these are the top branches with good placement and facility-

1- Applied Petroleum Engineering Upstream

2- Chemical Engineering Downstream

3- Automotive design engineering

But its not the matter of stream its actually the matter of interest, whether you're interested in these streams or not, there is too much students in these three streams in UPSES,  but these branch have high scope in UPES like private colleges but CSE has the scope all over the India. So just go with your interest, if you choose upper three then there is high chances that you get placed, and in CSE you can also be placed but not have a surety in UPES.

Best Of Luck!!!