Hello Aspirant,
See any candidate can appear for JEE-Advance maximum of two consecutive years after passing class 12th. Let us understand from an example, so if you have passed your class 12th in 2020 then you can only appear for JEE-Advance 2020 and JEE-Advance 2021.
For JEE-Main it is three years and twice a year means if you have passed your class 12th in 2020 then you are eligible for JEE-Main 2020, JEE-Main 2021 and JEE-Main 2022 means total of six attempts for JEE-Main.
I hope this information helps you.
Good Luck!!
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile