Hi Prakash,
we are using OD Clarity as well and I have cross verified all the existing DB tables in Clarity and I don't see On Demand Portal related tables(I think it's obvious because On Demand portal is altogether a different piece of Ca System).
As far as my knowledge goes true I doubt users who are using OD Model Clarity Application do have access to Portal Audit trial. As portal is administer by Ca team, I think it's good idea to contact Ca for any portal related details.
Best Regards
Jagadeesh