Is there a way to find out from Piriform number of devices and to disable the devices from Piriform server end?
If you are asking can they see if the number of devices allowed on a licence has been exceeded, and cancel the licence for such a breach of terms - then the answer is yes.
If you are asking about something else then please clarify.
Is this related to your other post about not being able to register? Is it telling you that the licence has been deactivated?
(There can be other reasons for a licence showing as 'deactivated', such as upgrading to a new licence, eg from Pro to Pro Plus, so the old one gets cancelled).