@himanshu-rathore All the information was given in the Rules section of the registration page. Copy of resident registration could be like AAdhar Card, Driving license, Voter Card and similar legal document. The Rule no. 2.2 states the below.
Each squad must submit a participating list of four (4) to five (5) players (further “Roster”) until a due date assigned by the MET. Only players registered in the roster is allowed participate in the tournament and must have a proof of a participating country citizenship.
You must provide at least one of the followings to prove that you are either a citizen or a legal resident:
Social security card
Copy of resident registration
Teams must provide requested information about the players which includes player’s name, date of birth, steam account, steam account number, in-game nickname, contact number, etc. Submitted roster is valid until the end date of the tournament.