This situation can be quite complex and the resolution may depend on the specific labor laws of your country. Generally, if an employee is relieved of his duties without serving the notice period, the company is usually obligated to pay him for the notice period, as per the terms mentioned in the appointment letter.
However, if the employee has been terminated due to misconduct or any other serious issue, the company may not be required to pay the notice period salary, depending on the employment contract and local labor laws.
In your case, if the employee was removed without any misconduct and without serving the notice period, he may be legally entitled to the 3 months salary. It would be advisable to consult with a labor law expert or attorney to get a more precise understanding of the laws applicable in your region.
Remember, it's always important to treat employees fairly and in accordance with labor laws to maintain a positive work environment and avoid potential legal issues.