8 hours a day, does not include lunch break etc.
48 hours/week.
Usually companies mention in the appointment letter workdays in a week and office timings or in circulars. If the company has given it in writing that wordays shall be 5 day/week,and has not withdrawn it in writing, then it is a seperate matter.
Is this firm registered in India and has it taken mandatory licences and displayed the same at the entrance/reception.
The employees must be signing date and time of entry and exit in the register or punching their matrix cards.
Companies usually assign the designation of executive/manager to the employees to give impression that they are not workman and hence not eligible for overtime.However the labor act and nature of duties etc shall determine the category of employee.
The employee/s being forced can lodge a complaint with labor authorities. They shall do the needful.