Yes, just as long as the game and its files can be accessed through itchio! :)
People have made their TTRPGs available by providing the rulebooks and other necessary content through PDFs. You can look for some examples in the physical games section! https://itch.io/physical-games
If your game must be hosted off the website in order to be played, then I apologize but it cannot be submitted to this jam as we must be able to verify each entry