It is per role, so if the user has the correct role he can access it, the others won't be able to see it.
Please see the doc
My requirement is user should not modify the page and portlet. it should be controlled by admin privilage user only.
Is there any document for jboss portal database table structure? How do i create a page thru SQL query?
That's the default behavior, only the admin change the page and windows of the portal.
Please read the documentation.