I have attached a sample appointment letter generated from greytHR at [URL](https://www.greythr.com/in/features/letters/). Accordingly, you can draft it for both categories. Based on your requirements, I suggest checking out an HR software that will help you save time and manual effort. greytHR is one such software that comes with various modules to help simplify the workflow in an organization. It includes a prebuilt letter template gallery, ready-to-use templates, and much more, making the job of an HR professional easier.
Thank you.