Hi Santosh,
If you go to Administration & Portlet Page you will see some portlets are system restricted and some are not and those are also portet provided out of box. So if you query the table CMN_PORTLETS and exclude created by 1 which is admin. It will give you the results created by users.
However if you have some one using admin to create the portlets then there will be mismatch.
Regards
Suman Pramanik