Holding Salary for not serving Notice period - Is there Any Laws related to this?

Can anyone suggest me on the Situation, if an employee leaves for his personal issue just after 15 days of joining, stated his family problem as a reason, Is it possible to hold his salary?
In appointment letter its clearly stated that if he doesnt serve his notice period he has to pay 2 months salary.
"You will be required to give two months’ notice of resignation to the company and provide a seamless transition to another designated company personnel or pay to the company two month’s all-inclusive salary in lieu of the notice along with all the expenses for training and other employee benefits you have received since your joining the company."
Note: He has not submitted his signed appointment copy back.
Is there Any Laws related to this , kindly advise.

Pl withhold his salary and any special payment, also writing to him to serve the remaining notice period failing which the dues payable to him shall be forfeited to that extent.

If in case of abscond, he is not ready to serve any period of notice, how can we handle it legally.

Pl be very clear that mere absence for the specified number of days cannot automatically lead to the presumption of abandonment by the employee. You will have to issue him notice of unauthorised absence and threaten action under the abandonment clause before you actually terminate the service. In your termination letter, it is better to specifically mention that as the employee has failed to serve the notice period, the dues payable to him shall be forfeited to that extent. In cases of abandonment, the notice period is not served by the employees and hence adjustment of notice period from dues like remaining salary, bonus, incentive payment, salary revision arrears, leave salary etc could be attempted.