As the very name suggests an appointment letter is the letter of intimation addressed to the selected candidate after the final process of selection. It should, therefore, contain important particulars like the specific job/post for which the appointee is selected, general and specific duties/responsibilities attached to it, the salary offered for the job, the status of employment i.e temporary/permanent/fixed term contract etc, the period of probation if any and the conditions for confirmation, conditions of unilateral and bilateral termination of the contract of employment, the time line within which the selected candidate should report for duty etc. What is therefore essentially implied is that the letter of appointment should be issued by the employer soon after selection and before the joining of the prospective employee. The fear of attrition can not be a valid reason either for withholding of appointment letter even after joining or confirmation after completion of probation by the employee. Failure to do so would end up in conflicts like the one of your RSM's resignation and may culminate in unnecessary litigation.
4th November 2016 From India, Salem