The last date for filing of ITR is being extended till 5th August 2017, by Income tax department of India
The linking will become mandatory from July 1, and it’s not mandatory to link before July 1. If you are not able to link it before July 1, your PAN will not become invalid automatically. After July 1, the linking will become mandatory and the government may declare a date after which the PAN not linked to Aadhaar will become invalid. The government has not declared that date yet.