[Moudix]

Alright i'll give you few ideas..
first , on top :

PHP код:

new cmdpossible[MAX_PLAYERS] 


OnGameModeInit()

PHP код:

cmdpossible[playerid] = 1; 


OnPlayerConnect :

PHP код:

cmdpossible[playerid] = 1; 


Now when the player types the command, you need to add this :

PHP код:

if(cmdpossible[playerid] == 1)
{
// your codes here etc.. then add the following :
cmdpossible[playerid] = 0;
SetTimerEx("waittimer", 300000, false, "i", playerid); //here i made it for you 5minutes you can change it.
}
else
{
SendClientMessage(playerid, COLOR_RED, "You need to wait 5 minutes before using this command again." 


Now somewhere but not under any callback :

PHP код:

forward waittimer(playerid);
public waittimer(playerid)
{
   cmdpossible[playerid] = 1;
} 


Just edit it if needed, i just gave few ideas on how to make it. Good luck!