The year in which you are attempting your boards examination will be the year of your first attempt.

Now you are saying 2021-22 this can mean two different thing that you are getting in 11 in 2021-22 or you are in 12 and attempting for your boards in 2022.

For the first case the first attempt for JEE MAINS will be the year 2023 i.e., JEE MAINS 2023. For the second case, the first attempt will be in 2022 ie., JEE MAINS 2022.

For JEE MAINS 2022 preparation tips visit the link below:

https://engineering.careers360.com/articles/jee-main-preparation-tips

To know more about JEE MAINS 2022 visit the link below:

https://engineering.careers360.com/articles/jee-main-2022#:~:text=JEE%20Main%202022%20Eligibility%20Criteria,-Particulars&text=Candidates%20should%20have%20passed%20class,2021%2C%20or%20appearing%20in%202022.&text=There%20is%20no%20age%20limit.&text=The%20candidates%20should%20have%20qualified,Language

I hope this answer helps. All the very best for your future endeavors!