As of October 17,2017, countless Aadhaar cards that could not be delivered were lying with the General Post Office in Shillong. The reason for the cards being undeliverable was that the addresses on the cards were not complete with most of them just mentioning “Shillong”. While the actual number of cards is not known, the Government of Meghalaya said that the localities under the delivery jurisdiction of Shillong GPO . Persons staying in the above localities who had enrolled for Aadhaar cards were asked to collect the same from the Shillong General Post Office.
Note, this basically means that the “address proof” of those Aadhaars would be completely unverified.
— source aadhaar.fail