This question is impossible to answer. It is just to generic.
It is like. "I want to build a villa with a nice garden. What do I need?".
Start with the beginning.
What type of PLC are you using?
Do you know some infomration what sort of protocols can be send from the Xbox?
How can you program in the Xbox that it can communicate. Which types of pyshical bus types and protocols can be used or designed? Like ethernet, RS232, USB etc. etc..
Idem for the PLC being used.
Etc. etc. etc..
If yoy then encounters some specific problems, like how can connect an active low RS232 connection to an active high RS232 for Xbox to PLC, we can help you.