Section 2A(2)(a) in THE PAYMENT OF GRATUITY ACT, 1972
(a)for the said period of one year, if the employee during the period of twelve calendar months preceding the date with reference to which calculation is to be made, has actually worked under the employer for not less than-(i)one hundred and ninety days, in the case of an employee employed below the ground in a mine or in an establishment which works for less than six days in a week; and(ii)two hundred and forty days, in any other case;