Relief u/s 89(1)

Gangadhar Rao Yaddanapudi (38 Points)

31 December 2019  
One of my clients, a Railway Driver received Rs.3,30,000 towards mileage arrears in the month of April,2019. The arrears releting to FY.2017 and 2018. Now can he claim relief u/s 89(1) ?. Also what are the documents required to upload along with IT Return ? Please explain.