Hello ,

See , for JEE Mains every candidate has 3 attempts . One in year you are appearing for 12th exam and next  two consecutive year , if you don't appear in any of them due to any reason your one chance is gone , so now you have two chances left one next year and another next  to next year . Means you can give JEE Mains in 2021 and 2022 both .

But keep in mind JEE Advance only give you 2 chances so you was unable to appear  now this year you have only one chance left that is next year . So you can give JEE Advance in 2021 but not in 2022 .

Hope this will help you.

Thanks .