JEE Main

Hi,
As you have not appeared in JEE Mains exam, you cannot get admission in any government college. I will suggest you to go for Lovely Professional University and appear for LPU-NEST exam. You will easily get a seat in B.Tech there. If you perform well in the LPU entrance, then you will get scholarship also.

Yes, you can take admission for BCA on the basis of your 12th grade. JEE Mains exam is not required for BCA.
There are many universities that offer BCA like Amity University, JIMS University and many more.

You can refer the link mentioned here:
https://www.shiksha.com/university/gjust-guru-jambheshwar-university-of-science-and-technology-hisar-3273

Yes, you can get admission in UPES for petroleum engineering.

Please say your category for better guidance otherwise it is impossible to say about it. You can have an idea by trying Shiksha's college predictor.

Your percentage is not good enough to get the best colleges. Just go through the link that is mentioned here:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

Verify the link:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor
Go through the above mentioned link with your percentage.

As your rank is pretty high, you have to move to some private institutions. The average salary is around 1 lakh per year, therefore a total of 4 lakhs. As the amount is very much considerable, choose your college wisely in terms of ambience and placement.

Yes, you can get in SASTRA University.
But we request you to attend the counselling session as it gives you a greater chance of getting admission
Hopefully, this answers your question.
Thank you.