How to claim leave encashment exemption?

In case of an employee of the central govt. state govt. any amount received as cash equivalent of leave salary at the time of retirement is exempt.

for non govt employee certain conditions are applicable to claim exemption

if leave salary is exempt in your case then

1.   leave salary is exempt from tax under sec 10(10AA)(i)
      in income tax return (ITR-1) , you can mention amount of leave salary as exempt income.

2     It should be mentioned ITR-1 in Line No. D-20 : Exempt Income only for Reporting Purpose

      (If agricultural income is more than Rs. 5000/- use ITR-2 or 2A)