The "staffs" are covered as per the terms given in the Appointment letter as long as they are not considered as "Workmen" as specified by The Factories Act, 1948.
They can be asked to leave the company in two ways.
1. By asking them to give a resignation letter by themselves notifing some personal reason
2. Or by termination letter issued by management mentioning his poor performance or his inability to give output as expected by the management.
In both cases the first one is safe. As a staff he cannot approach the labour court for any grievences. But he can appeal in Civil Court and it will take a long time to win a case.
From France , Issy-les-moulineaux
I believe that the "Officers" are bound the terms of the appointment letter. There is a window of opportunity to notify the Company of their intention to leave, "a minimum of one month and a maximum of three months. . . " Consequently, an Officer with more than 3 years of service, as in your case, can submit a resignation letter in as little as one month, but may have a liability of three months "payment in lieu".
However, if the Officer submits his letter, it would be up to the Company to release him (with payment in lieu, if any) at a time most convenient to management.
From United States , Redmond
Many a times an employee is designated as Officer whereas he is doing merely clerical or supervisory duties. One needs to examine if he is not coming within the purview of Section 2(s) I.D. Act. This will be determined by his nature of duties not merely the nomenclature. If he is doing duties mainly of a managerial nature or administrative duty, he will not be a workman. In that case you can resort to simple termination by following the notice clause of the appointment letter.
From India , Pune