i am currently in class 12 2020 I was appearing for class 12 board exam on 2021 if I forgot to give jee 2021 as I did not study for it in class 12 , is all the 3 attempt lost or 2 attempt remains for 2022 and 2023. please give positive information about it is I am able to take her in 2022 or not

Dear student,

As you are still currently studying in class 12th and you have not given your class 12th boards exams yet, then you have still 3 attempts left that is JEE mains 2021, JEE mains 2022, and JEE mains 2023.

Because in JEE mains you can give maximum up to three attempts counting from your class 12th passing year.

Still if your doubt is not cleared then here let's take an example -
If you are currently studying in class 12th this year 2020 (as you said), so you will pass your class 12th in 2021, your board marksheet will come in the year 2021 then your class 12th passing year is said to be 2021.
And in 2021 you can give your first attempt of Jee mains because if you are currently studying in class 12 there is no chance that you can give JEE mains 2020 as you are not eligible.
If you miss your jee mains 2021, then also your first attempt is counted as over. And after that you will be only left with two attempts, i.e, jee mains 2022 amd jee main 2023.
If you will pass your class 12th in 2021 then in 2021 give JEE mains and after that you would have two more attempts left that is JEE mains 2022 and jee mains 2023.
If you miss any then still you attempt will be counted as over.