Can I accept a project where I am required to pay salaries to my employees, but if I complete all the tasks on time and do overtime, I am allowed to keep all the money earned instead of paying those employees?
If the agreement between you and your employer states that, then you will be allowed to do so. Applying the agreement is must on you as well as your employer. You should never take or prevent the salary of any employee who did his job.
'Wassalam.