Hi Saravanan,
If all attempts from FSSUI fails, you could still try to delete them from WAM UI.
If WAM UI fails, then try XPSExplorer command line tool.
However, you should have policy store backed up first in case data corruption happens when using XPSExplorer to remove any store objects. This is small risk that siteminder admin has to consider.
When you go over these steps, repeatedly running XPSSweeper from time to time.
R12 version is known to have objects not linked or synced immediately while UI changes are happening, XPSSweeper can mitigate to some degree. R12.52 or later release will improve this feature much better.
Hope this help.
Thanks,
Hongxu