@Zain *****
The 90-days report is a "Notification of staying in the Kingdom for more than 90 days". It is done by filling in immigration form TM47.
"An alien who has been granted permission to temporarily reside in the Kingdom, if staying in the Kingdom for more than 90 days, that alien has a duty to report his/her residence to an Immigration Bureau officer every 90 days.
This is in accordance with Section 37(5) of the Immigration Act B.E. 2522."