As we know, India, there are different labour laws applicable to various types/sizes/nature of establishments. Despite the facts, I don't think Indian law enforcing authorities/courts would recognise a situation 'No leave Policy' for whatsoever may be the categories of employees/nature of work, except when they are not to be considered as 'employees'. Atleast on records there should be rules to show they are entitled to leave though de-facto such managerial persons are on 24x7 schedule such as consultants, doctors etc. If they are not on duty they'll be treated as on off or on leave, flexible, otherwise they would be available irrespective of time & day.