[Brightcolours]

Canon R5 and R6 share the same battery grip BG-r10
https://shop.usa.canon.com/shop/en/catal...rip-bg-r10
which is new for Canon usually they have a grip per camera let's see if other future cameras will be compatible with it.

However they have another grip with LAN and WIFI that only works with R5 : "Wireless File Transmitter WFT-R10A"
https://www.usa.canon.com/internet/porta...r-wft-r10a

Not really... Canon EOS 5D mk III, 5DS, 5Ds R same battery grip BG-E11.
Canon EOS 70D, 80D, 90D, same battery grip BG-E14.
Canon EOS 750D/760D same battery grip (BG-E18).

As long as the form factor and the battery technology are the same, Canon would use the same battery grip.
The R6 misses the internals for the LAN connection, hence that grip only is for the R5.