Tds Deduction On Salary For An NRI With inoperative Pan

There is an employee who is working with us and is an NRI(Srilanka). Due to govt new rules his pan number has been inoperative as per the software is showing. He is leaving now and got total gross income of Rs. 606332. As per the new regime there is no tds upto Rs. 7lpa but just because the pan is inoperative shall we need to deduct tds on higher rate which is actually 20%? and what will be the threshold income limit?