No, it is not allowed. If you want to give JEE Advanced in specific year, you have to give JEE Mains exams in that year. If you have qualified JEE Mains in 2021, i suggest you to give advanced in 2021 only. Next year, you may or may not be eligible for exam.

Hello,

Yes, you can eligible to appear in JEE ADVANCED in next year. See you can appeared for JEE MAIN through 3 consequtive years after the boards . It is same for JEE Adv. So don't worry and start your preparation. You can eligible for jee adv for next 3 years.

Hope for the best.

Thank you.