Update your Bookmarks to https://sites.google.com/view/gam--commands/home
gam print chromepolicies ou </Path/To/OU> todrive
Investigate inherited policies for Sub-OUs
gam print chromepolicies ou </Path/To/Sub-OU> show inherited todrive
The first language in the list will be used as the default language for the newly signed-in users.
gam update chromepolicy chrome.users.AllowedLanguages allowedlanguages ""<Allowed Languages, Comma Separated>"" ou "</Path/To/OU>"