If you wish to appear for the JEE ADVANCED examination, then you have to mandatorily clear the JEE MAINS examination and need to clear the JEE MAINS cut off for the JEE ADVANCED examination.

Now for JEE MAINS there are a maximum of 3 consecutive attempts and for JEE ADVANCED there are 2 consecutive attempts. After this you can attempt and the first attempt is considered the attempt you give in your Board examination year (even if you don't appear in the board year for JEE, then also that will counted as first attempt).

For more information regarding JEE MAINS consider the link below:

https://engineering.careers360.com/exams/jee-main

For more information regarding JEE ADVANCED consider the link below:

https://engineering.careers360.com/exams/jee-advanced

I hope this helps. Wish you a great eve!