If your POC involves using applications both inside and outside of Citrix, then you would need to read up on our Citrix context and how that works. You didn't actually mention that though, so I am not sure you meant to ask about Citrix since your subject is rather different.
For a POC, you don't really need to setup the Pega Platform and Robot Manager to provide the work, as really what you are demonstrating is whether a bot can perform the steps required. If you do in-fact want or need Robot Manager for your POC, you will need to install the latest Pega Platform and Robot Manager application. You'll need a Windows machine to install Package Server on (it can be your own machine). Those are the main components you'd need for a POC.