The statutory provision regarding leave with wages is given in Section 80 of the Factories Act 1948. It provides for payment of Basic Pay and DA. It cannot be CTC as CTC is a much broader concept and includes many more items than is provided for in the calculation of leave salary. Indeed, the Act specifically excludes bonus and overtime payment, but CTC would include it. For reference, Section 80 of the Act is extracted below:
Wages during leave period
(1) For the leave allowed to him under [section 78 or section 79,] as the case may be, a worker shall be entitled to wages at a rate equal to the daily average of his total full-time earnings for the day on which he actually worked during the months immediately preceding his leave, exclusive of any overtime and bonus but inclusive of dearness allowance and the cash equivalent of advantage accruing through the concessional sale to the worker of food grains and other articles.
(2) The cash equivalent of the advantage accruing through the concessional sale to the worker of food grains and other articles shall be computed as often as may be prescribed, on the basis of the maximum quantity of food grains and other articles admissible to a standard family.
Explanation 1: "Standard family" means a family consisting of a worker, his or her spouse, and two children below the age of fourteen years requiring in all three adult consumption units.
Explanation 2: "Adult consumption unit" means the consumption of a male above the age of fourteen years; and the consumption unit of a female above the age of fourteen years, and that child below the age of fourteen years shall be calculated at the rates of 0.8 and 0.6 respectively of one adult consumption unit.
(3) The State Government may make rules prescribing the manner in which the cash equivalent of the advantage accruing through the concessional sale to a worker of food grains and other articles shall be computed; and the registers that shall be maintained in a factory for the purpose of securing compliance with the provisions of this section.