Hello Aspirant, Hope you are doing good.

1. As per your query,  You can give JEE Mains Exam 12 times over three consecutive years. each year you will get 4 chances that are in February, March, April, and  May.
2. you get 3 chances to write the JEE MAIN exam out of which 1 chance is still left with you, you can improve your score with your last attempt.
3. But according to JEE Mains it is important to have a minimum of 75%  IN YOUR 12TH board, Improvement Exam is taken only for the candidates who appeared consecutive previous year's main exam of class 12  that is, you can only give this exam next year of class 12. You can only give it only one time, next year of class 12 exam

Hope this is helpful, Feel free to ask any queries.