its under server/other.cfg
Might wanna set the the limit low so people don't kill teammates on purpose
//******************************************************************************
// TEAM KILL MONITOR
//******************************************************************************
// Enables the team kill monitor
// 0 = Disabled (default), 1-10 = Limit before the player is punished
// set scr_tk_limit "10"
// Duration of the punishment (some punishments do not use this time)
// Allowed vlaues: 0-60 (default is 30)
// set scr_tk_punishment_time "30"
// Controls whether multiple teamkills using grenades or explosives should count as one or not
// 0 = Disabled (default), 1 = Enabled
// set scr_tk_explosive_countasone "0"
// This variable controls what punishment will be applied to a player that has
// reached the maximum number of team kills allowed. Once the punishment is applied
// the team kill counter will start from zero again.
// 0 = Warning message (default)
// 1 = Player's weapons are disabled during the set punishment time.
// 2 = Player is frozen in the current position for the set punishment time. Player can still use weapons.
// 3 = Player is killed on the spot.
// 4 = Player is kicked from the server.
// set scr_tk_punishment "1"