You want to know if there's a way to create an account with the view (read-only) privilege in the portal admin console:
https://<HOST>:<port>/sigma/admin
Identity Portal 14.x & v15
There is not a 'view only' permission for either the Portal Administration page. Users are either granted full Admin rights or they cannot access those the admin page at all.
This could be submitted as an enhancement for consideration in a future release.
To submit an enhancement; please submit a new 'Idea' to the Broadcom product communities in the Ideation area:
Create Idea - Enhancement request
Click 'Add' button on the right side of the page, Provide a Title, and detail regarding the requested enhancement to the software, including business requirements, screenshots if and where relevant. Select Symantec Identity Management from the Categories list and submit.