Dear Nilesh,
I would request you to go through the provisions of sec.4(6) of the Payment of Gratuity Act,1972 and analyse it critically as well as carefully.
The alleged act of leaking confidential data of the employer's establishment by the employee and your dilemma as whether to hold the employee's gratuity or not indicates the position that his employment has come to an end. Not every termination of employment of an employee would attract the provisions of sec.4(6) of the Act even if any one or the others of the misconducts mentioned respectively in its clauses (a) and (b) respectively are present. Only when his services have been terminated by the employer on account of the misconducts mentioned therein, the employer can resort to partial or total accordingly. Therefore, the termination of his services should, already, have been as a measure of punishment for committing such misconducts enumerated.