You can get yourself enrolled in any engineering college to become an engineer because since last year in JEE mains, 12th marks aren't being considered. You can still sit for JEE mains and get a decent college. Since you have secured 58% in 12th, I feel that your basics aren't clear and you need to work on your 12th first. Though, 12th marks doesn't matter but whatever you secure in 12th gives a deeper insight of how much you have understood your 12th subjects. I would suggest you to work hard and make your concepts clear and then sit for paper. Then only, you might be able to get yourself in any prestigious engineering college.