cony25

Can I use the new Rmount adaptor with a EFL 70-200 mm that I currently use on my Canon 80d?
The camera that I need to use the adaptor is an the efl lens is an EOS R mount.

CHG_CANON Loc: the Windy City

The mirrorless EOS-R cameras are now all an RF mount, although we're unsure what mirrorless camera you're considering. The EF to RF adapter is needed for either EF or EF-S lenses onto an EOS-R mirrorless body. The adapter (any of the three Canon options) provides mount points for both the EF (red dot) or EF-S (white square) into an RF mount EOS body. Unlike the EF-S mount, the RF-S lenses mount to the same RF mount as the full-frame EOS-R EOS bodies. The new RF-S lenses just produce a smaller image circle, similar to Nikon's DX line of lines.

Architect1776 Loc: In my mind

Yes, you can use the EF-RF with any EF or EF-S lens on your RF mount body.
Your 70-200mm lens will work just fine if it has no other issues.
I got the control ring adapter version as it adds RF lens features to all my EF lenses.
So get the adapter and go forth and have fun.