can you tell me the correct procedure on how an employer has to pay retainer to their employees at university

Answer 1

If you are asking about employees of a company that has nothing to do with the university, who take classes that will improve their skills and qualifications at the employer, then the employer has no legal obligation to pay anything to the employees for this education, but many do.

It is not unusual for an employer to compensate employees for some of the expense of education in topics that will help the employee become more skilled at the employee job. Compensation might be a portion of the total expenses, might be a oercentage based on grade level ... e.g. C or below get nothing, B get paid 25% of the education cost, A get paid 50% of the education cost.

It may be that this question belongs in Business / Careers or some area of Education sub-category, not in law & ethics.

Answer 2

In the US an employer has no obligation to pay a retainer for an employee attending school baring some sort of contractual agreement. In that case you would need to read the contract.