Avatar Setting

You will find the corresponding option inside:

Dashboard >> Reign Setting >> Community Settings >> Avatar Setting

You will find the following options inside it:

Default User Avatar

This  option allows users to upload an image that will be displayed as the default avatar for users who have not yet added a custom image to their profiles.

Default Group Avatar

Similarly, this option allows users to upload an image that will serve as the default avatar for groups before a custom image is added.