There are three questions asked, and Mr. Grover has answered most of them well. For more clarity, I am elaborating here.
Categories of Employees in India
There are two categories of employees in any establishment in India:
1. Workmen as defined under the Industrial Disputes Act.
2. Other employees who are not covered under this definition (generally termed as management staff/supervisory staff, etc.).
1. Workmen as defined under the ID Act are covered by the ID Act, Standing Orders Act, and the appointment letter.
2. Other employees will be covered by the terms of appointment and other circulars issued in the organization and are guided by the Indian Contract Act.
Examination of the Three Questions
A) Are appointment letter clauses enforceable in a court of law?
As explained by Mr. Grover, appointment letter clauses are enforceable in a court of law. In the case of workmen, it will be examined by a Labor Court, and the process to approach the Labor Court is through conciliation. In the case of other employees, the remedy has to be obtained through civil suits under the Contract Act.
B) Termination on the mere ground of employer discretion: Can it be justified, and if not, what can an employee do?
Termination at discretion is not legally correct. Termination on grounds of misconduct must be preceded by an enquiry, and principles of natural justice must have been complied with. Termination at the end of probation is legally correct both in respect of workmen and management staff. If a workman is not satisfied with termination, they can approach the conciliation officer under Sec 2(A) of the ID Act and through this process can approach the Labor Court. Other employees not covered under the ID Act can file a suit in the concerned Civil Court. Civil suits take a longer duration, but there is no other option available. Employees of Public Sector undertakings can approach High Courts by a writ, but this recourse is not available for other employees working in the private sector.
C) When an employee does not join after accepting an offer letter or even an appointment letter, can we do anything?
An offer letter and acceptance of an offer technically complete a contract. Unfortunately, most companies mention, "If you do not join on or before (date), this offer stands withdrawn." If this is the clause, then management cannot have any recourse through legal means as the clause clearly states that non-compliance will only end in management withdrawing the offer. Alternatively, if management introduces a new clause specifying certain reasonable financial losses, then approaching the court is possible. However, no management generally would like to resort to such clauses as it will not attract new talents even to appear for an interview. Legal clauses do not always help.
Additional Question Raised by the Original Poster
Please advise if an employee coming under the purview of workmen does not give one month's notice before leaving the company, can we legally hold his salary as he has signed an appointment letter which has a clause of one month's notice period.
Holding notice period salary is legally correct for all employees. In respect of workmen covered under the ID Act, companies' certified standing orders will be applicable more than the offer letter/appointment letter. If there are certified Standing Orders, then Model Standing Orders will be applicable, and most of the model standing orders provide for a 15-day notice period. However, kindly check the model standing orders in your State. For other employees, whatever is specified in the offer letter/appointment letter/or any subsequent circular which has been duly acknowledged by the employees will be applicable, and it is legal to hold/deduct notice period salary from final dues payable.
Regards.