[CarRamper]

Код:

if(strcmp(cmdtext, "/changegamemode") == 0) 
     {
         SendRconCommand("changemode nameofgamemodehere");
         return 1;
     }

I Think When i Will put This command under OnPlayerCommandText It Will Change The Gamemode of whole server.I Mean that gamemode of all the people who are playing at that time will get change>if yes tell me a command through which i the gamemode of a particular person can be changed

[MBilal]

You can't use different gamemode for different players.
But you can use different Virtual world for different players.
check that link below to see virtual world info
Link