Directly converting a file (a proprietary backup format used by Acronis Cyber Protect Home Office and modern Acronis True Image versions) into a bootable ISO image is not supported by standard conversion tools. Because .tibx files are archives designed for incremental backups rather than raw disc images, you cannot simply "rename" or "convert" them with standard software.
Boot into Acronis Bootable Media and restore the .tibx content to a spare partition or a Virtual Machine (VM). convert tibx to iso