FILING OF UPDATED RETURN FOR FY 19-20

He got notice from the department as there is high value transaction in fy 19-20, and the department mentioned to update return and pay tax. After calculating he got 2 lakhs of tax amount he is ready to pay but asking some time. The last date to file reply is today. So i have raised the above query. Is there any option sir to file now and pay tax later for updated returns.