new Count1,Count2;

public OnPlayerSpawn ( playerid ) {
    for(new i = 0; i < GetMaxPlayers(); i++)
      {
        if (gTeam[playerid] == TEAM_RED) Count1++;
        else if (gTeam[playerid] == TEAM_GREEN) Count2++;
      }
}

public OnPlayerRequestSpawn(playerid)
{

      if ((Count1 > Count2) && gTeam[playerid] == TEAM_GREEN)
      {
        SendClientMessage(playerid,COLOR_RED, "[BALANCER] Balancing teams. Choose Another Team");
        return 0;
      }
      else if ((Count2 > Count1) && gTeam[playerid] == TEAM_RED)
      {
        SendClientMessage(playerid,COLOR_RED, "[BALANCER] Balancing teams. Choose Another Team");
        return 0;
      }
    return 1;
}