On IW6-Mod, the search paths for custom game scripts are as follows:
ALL MODES:
scripts
SP:
scripts/sp
scripts/sp/<level name>
MP:
scripts/mp
scripts/mp/<level name>
scripts/mp/<game type>
Unlike IW4x, IW4x-SP, and IW5-Mod, the IW6-Mod (and S1-Mod) do not have a userraw folder.
Take IW6-Mod as an example:
The base folder for GSC scripts is simply the iw6 folder. This folder likely already exists in your game directory. If it doesn’t, you can create it manually like this:
Call of Duty Ghosts/iw6/scripts/mp/example.gsc