Do you need the or just the XenCenter management client ?
Due to the version's EOL status, the ISO is no longer featured prominently on the primary Citrix download portals. Locating the software requires specific steps: xenserver 7.6 iso download
While I cannot "develop" a new software feature for Citrix XenServer, I can highlight the most "useful" updates introduced in the and provide the necessary resources for downloading and installing it. Key Useful Features in XenServer 7.6 XenServer 7