Dear Jaya,
Please try to understand. Overtime is given to the workers and not for the Managerial/Supervisory Staff. The time fixation is done mainly for those who are engaged in hard and strenuous work. If they continue for more than a certain time period, it will reduce their effectiveness and productivity, and further, it may lead to accidents at the workplace. To avoid such exploitation, the government has made some stringent rules. However, as the Managerial/Supervisory staff are qualified and their work is not as physically stressful, it does not cause damage to the company. Hence, overtime is designed for the workers.
While making such Acts, Rules & Regulations, the government creates them with some sense. But whether they are followed during implementation is in the hands of the authorities.
That's the reason workers are given bonuses, whereas the Managerial staff are not. Instead, they receive ex-gratia for the period.
What about a medical officer in a PSU who does stressful work for a long period, sometimes compromising on sleep, and is also in a managerial capacity?