Hello Niket,

JEE doesn't require a topper on the other hand you just need to have passed your class 12th exams that's it. If you are truly determined to go into any bigger institution for engineering like IIT DELHI then yes you have to get really good marks in IIT JEE. 

Now coming to your question since you have passed your class 12th in 2018 so now according to me you should not waste your time doing back all of it again because that option is worst I think now since you can't go for improvement also so you should atleast take admission in some lower institution or other course and you can try for jee again.

Hello Aspirant, yes you can do the intermediate and then you can give the exam of jee main. NTA merged the JEE Main January and April scores to prepare the final merit list. The first paper held in month of January and the second paper will held in the month of April. 

I hope this will help you.