R500 is 11ac wave1 AP, it only can support to 200.7 version. But R650 is introduced in Unleashed 200.9. So those 2 AP can not work together.
My suggestion is: you can set R610 as master, then remove R500, and upgrade the network, then join in R650. Or you only can set 2 Unleashed network in 2 different sub-net.