U/s. 16(ia) of IT act (Note: New ITR forms for AY 2019-20 will be amended accordingly.)
For your reference the section is reproduced hereunder::
Deductions from salaries.
16. The income chargeable under the head "Salaries" shall be computed after making the following deductions, namely :—
(i) [***]
Following clause (ia) shall be inserted after clause (i) of section 16 by the Finance Act, 2018, w.e.f. 1-4-2019 :
(ia) a deduction of forty thousand rupees or the amount of the salary, whichever is less;
(ii) a deduction in respect of any allowance in the nature of an entertainment allowance specifically granted by an employer to the assessee who is in receipt of a salary from the Government, a sum equal to one-fifth of his salary (exclusive of any allowance, benefit or other perquisite) or five thousand rupees, whichever is less;
(iii) a deduction of any sum paid by the assessee on account of a tax on employment within the meaning of clause (2) of article 276 of the Constitution, leviable by or under any law.