Hi Kiru,
What do you mean "custom Icon in the tab"?
Do you mean favicon?
If so, PPM use below ico file as favicon.
<PPM_directory>/webroot/ui/images/shortcut.ico
<PPM_directory>/webroot/ui/uitk/images/shortcut.ico
If you replace it to your original ico file with the same name (shortcut.ico), you will see your ico image on all PPM tabs.
Regards,
Shoichi