If you are on a Google Apps for Nonprofits or Google Apps for Work domain - Your access is driven by what Google Groups you belong to.

Here is an introduction to Google Groups - by Google Apps. Please start with these official Google training materials before submitting a ticket. The answer I give you will probably be something I looked up there and will link you to.

If after reviewing Google's Documentation and training materials on Google Groups from that last link you still need some clarity check out this playlist.