SetPlayerWorldBounds(playerid,Float:x_max,Float:x_min,Float:y_max,Float:y_min)

public OnPlayerSpawn(playerid)
{
  SetPlayerWorldBounds(playerid,1994.9497,1839.3379,-1333.2124,-1472.2440);
  return 1;
}

Above OnGameModeInit:
new GTA;

//OnGameModeInit Insert
public OnGameModeInit() {
     GTA = GangZoneCreate(-2977,858, -2931,147, 2931,147, 2954,502);
     return 1;
}
// Player Spawn
public OnPlayerSpawn(playerid) {
     GangZoneShowForPlayer(playerid, GTA, 0x00FF0096);
     return 1;
}
//======================