Form 16A for non salary deduction is to be issued within 15 days of filing the quarterly returns.
However as per the Income Tax department in case of Form 16 (for salary deduction) the due date as per rule 31 was 31st May, 2017 which was the same as the due date to file TDS return for the last i.e 4th quarter.
The Income Tax department has revised the last day to issue Form 16 by 15 days i.e. to 15th June 2017.
To read the notification click here