All Greek Domain Names registrations are subject for approval from ΕΕΤΤ, the Greek Government Authority for Domain Registrations. The approvals are made twice a month.
That means that you should wait about 2 - 4 weeks to be sure that EETT will not disapprove and cancel your registration.

With our Domain Names Check Service a Domains Consultant checks if your registration is valid according to EETT regulations so that you are sure it will not be cancelled by EETT after 20 working days.