Hello,

For sure you can give the jee mains exam. For your all kind of doubts you can follow the articl here:-

https://engineering.careers360.com/articles/how-to-fill-jee-main-application-form

For your question you have the section where it will be written like:- "Appeared or appearing for improvement of 12th exam" you have to write yes there.

Fill up the form as per the guide.

Hope it helps!