I think the employers are using CTC just to make it attractive to their prospective employees. He need not mention CTC because when he does so as annual package without specifying any other condition such as per Payment of Gratuity Act etc., he binds himself in a specific contract with such an employee who may always want to get his package as per terms of his employment conditions and the employer may not be in a position to wriggle out of this contract even when the employee may not have completed the requisite statutory period as enumerated in the PGA. Who knows, the Controlling Authority under the PGA may view the matter eye to eye with the applicant.
I suggest that the employers should refrain from writing CTC and should clearly specify in the appointment letter to his employee, the amount of salary/wages he would be paid + the statutory benefits like PF, ESI, Bonus, Gratuity etc. Even if the employer does not mention CTC, the employee understands it and gets it in accordance with the applicable law.
Give it a thought.
Best wishes and regards