Criteria for Who are the employees eligible to get overtime pay?

Hi, I am working as Manager - HR in event industry (corporate event). We have set of employees designated as Account Manager, Copy Supervisor, Account Executive, Operations Manager, Group commercial Manager etc. Even though they are designated as Manager, but they do not have any subordinates to assist them. They themselves have to do their job.
My question is are these employees are eligible for overtime pay? Who are the employees eligible to get overtime pay ? Is there any criteria to decide on overtime pay based on employees designation ? Please advise.
Balaji A

If the role performed by employee is managerial in nature, then such person in not entitled for overtime wages.