[Gangs_Rocks]

Use OnPlayerShootPlayer for anti-teamattack
Use OnPlayerDeath for anti-teamKILL

like:
// OnPlayerDeath

if(GetPlayerTeam(killerid) == GetPlayerTeam(playerid))
{
SetPlayerHealth(killerid, -15);
SendClientMessage(killerid, RED, "You've been killed for killing a team mate! ");
SendClientMessage(playerid, RED, "You've been teamkilled. Position restored ");
}

do the rest code GetPlayerPos, SetPlayerpos and weapons and stuff.