Dear Basant,
I didn't understand your method of dividing the rate by 200. I believe that under the Factories Act, overtime (OT) is calculated at double the hourly average rate of wages. The hourly rate is determined by dividing the daily wages by 8, and the daily rate is calculated by dividing the monthly wages (Basic + DA only) by 30 or 26, depending on the case. As Ganeshhr pointed out, it may not necessarily be 26 days since the Factories Act does not specify it, unlike the Gratuity Act, where the daily rate is calculated by dividing the monthly salary by 26, regardless of whether the employee is monthly rated or daily rated. However, under other labor enactments, the daily rate of wages refers to monthly wages divided by 30 for monthly rated workers and by 26 for daily rated workers.
Regards,
Madhu.T.K