Hello,

If you have passed out 12th then first of all you have clear  JEE Mains exam and only after clearing this you are eligible for JEE Advanced.

Now coming to your question, if you want to appear FOR JEE Advanced in 2022 then you have to appear for JEE MAINS in 2022 too and if you rank would fall among between 250000 rankers then only you are eligible to apply for JEE Advanced other you are not. Yes, you can sit only for 2 consecutive years in JEE Advanced.  Here's the detailed eligibility for JEE advanced

1. Must have passed 12th class with Science.

2. Only top 250000 rankers of JEE Mains are eligible to apply.

3. The validity of JEE Mains score is valid only for the current session. Give the JEE MAINS in the same year.

The exam date of JEE ADVANCED has been released, have a look at the important dates of JEE ADVANCED

Paper1- July 3rd, 2021 Saturday 9:00- 12:00 IST

Paper-2 July 3rd, 2021 Saturday 14:30- 17:30 IST

For more information please go through this link

https://www.google.com/amp/s/engineering.careers360.com/articles/jee-advanced/amp

God luck.