The government has extended the deadline of linking the pan card to the aadhaar card from 31st December 2017 to 31st March 2018.
As of November, 13.28 crore out of 33 crore PANs have been linked to the 12-digit biometric identifier Aadhaar.
This year, the government made quoting of Aadhaar mandatory for filing income tax returns (ITRs) as well as obtaining a new PAN.
Section 139 AA (2) of the Income Tax Act says that every person having PAN as on July 1, 2017, and eligible to obtain Aadhaar, must intimate his Aadhaar number to the tax authorities.
Reference : https://timesofindia.indiatimes.com/india/deadline-for-pan-aadhaar-linkage-extended-to-march-31/articleshow/61978092.cms