You can run an LTSR Controller with CR VDAs (for testing), but the reverse is unsupported. Always check the Citrix Product Matrix for compatibility.
Version 2603 is the latest "Current Release," offering the newest HDX enhancements and administrative tools. citrix latest version
Citrix has recently released the latest version of its virtualization solution, Citrix Virtual Apps and Desktops 2203 Long Term Service Release (LTSR). This new version provides a range of exciting features and enhancements to improve the user experience, security, and manageability of virtualized applications and desktops. You can run an LTSR Controller with CR