Dear Ishita,
You can develop your standing order (if applicable to your company). Otherwise, you can purchase the model code of conduct of your state and then develop accordingly to your company rules and regulations, but all the matters should comply with legal law. Regarding format and other things, you can develop your company's internal code of conduct.
Please find attached the code of conduct for suppliers (for the Next client to suppliers). You can take help to understand how social and ethical requirements are communicated, and you can add all your HR-related policies of your company with all legal activities accordingly (your focus should be company to employee).
In case you encounter any problems, please let me know, and you can contact our branch offices which cover almost all major cities; our representative will assist you.
Best Regards,
Sajid Ansari
Delhi