Hi Vinay,
As we understand, every company will have different styles of formulating their company policies. The sample policy that I have mailed to you consists of Mobile instrument + SIM (prepaid or postpaid) depending on the company norms for the middle and top management. In case you want to provide your employees only with SIM cards, then you should specify the SIM usage and their style of usage, along with the limit that they can use at actuals. At the end of the month, they should submit the company with the mobile bill, including their personal and professional calls duly marked on the bill. Do not forget to mention the usage limit.
If you wish, you can prepare a rough sketch and send it to me via email. I can make necessary changes and provide inputs wherever required.
Regards,
Pooja