User Manager V5 with Hotspot V6?

I have running centralized User Manager V5.26, and all my current routers also running V5.26.
Now I need to connect CCR to my User Manager. CCR can’t run V5, and Centralized User Manager must run 24/7 without downtime so User Manager can’t go V6.
Question is, can I connect CCR V6.32.3 to User Manager V5.26? Any problem can occured?
Thanks.