While cryptainers can be created as a "cleartext" (unencrypted) container, that's NOT the default. So, if you can prove that all cryptainers have encryption enabled, you've satisified the audit request.
To do this, run a cryptainer list command from the CLI, or view the cryptainers in the web GUI. If there is an 'e' in the Options, it is encrypted.
Depending on the type of cryptainer (iscsi, nfs, fc), you may have to modify the command. For example, for iscsi it is iscsi cryptainer list
The FC1020 CLI manual should have all options for you. Are you encrypting fiber activity to tape, or disk volumes?