I figured it out and thought I should share with the community how it works since no one has answered yet.
Basically in the data folder in the t6r folder create a maps folder and then inside that folder create an mp folder and finally inside that folder create a gametypes folder (if your running a zombies server add _zm to the folder name ), then use something like GSC studio to compile your script and name it _clientids.gsc.

It should look like something like this.

My friends and I are trying to make a mod that would force team auto balancing in grief since right now players always end up on the same team. However, since there isn’t any documentation on how Plutonium servers load custom GSCs we haven’t
been able to do much yet.