Hello,

The first phase JEE Main was held from February 23 to 26, 2021 in which 652627 students had participated.In the second phase a total of 619638 candidates had registered.In third phase 7,09,519 candidates registered and in final phase, more than 7.30 lakhs candidates registered. The exact figure of unique number of attempts taken hasn't been released by NTA yet.

I hope this helps.