Hello Candidate,
For most of the Private colleges eligibility criteria for engineering is to Pass with 60% aggregate marks in 10+2 with PCM and for other courses it is around 50%.
Though most of them have management quotas, they also highly consider JEE main marks for engineering.
So for now, you should concentrate and prepare for your 12th boards.
all the best :)

First and foremost, focus on completing your 12th standard. And not just completing it, but completing it well. Almost every Engineering or other college takes into consideration your 12th board marks as well as your marks in competitive exams. You can prepare for competitive exams parallel to your board preparations. It's also important to know where your interest lies and what fields you can see yourself working in and make decisions accordingly.