Searches for "Xbox BIOS files for xemu new" often lead to broken links, malware-laden file hosting sites, or Reddit threads that are months old. The community is tight-lipped because sharing these files violates the rules of almost every major emulation forum (like r/emulation) due to copyright risks.
Distributing these files is a violation of copyright law, so you must source them yourself. Required Files | xemu: Original Xbox Emulator xbox bios files for xemu new