Simple, You can fill JEE Mains form in next year if you will be eligible for itJEE Mains is conducted by CBSE that is very strict to their given last datesBut Dont Be DemotivatedYOU CAN FILL FORMS OF VARIOUS OTHER COMPETITIVE EXAMS like states engineering exams and private institutes engineeringLive may have some other plan for you, who knowsSo Keep TryingAll The Best!