It is now possible to queue for Crossplay Multiplayer Quick Match : r/Rainbow6

Top 5 multiplayer games that support cross-platform play

For Honor CROSSPLAY FAQ

Warzone, How To Crossplay

Does Rainbow Six Siege have crossplay? — SiegeGG

Rainbow Six Siege crossplay: how to play with friends across platforms

The best free Xbox games (December 2023)

Splitgate' Is Halo Meets Portal, Free To Play On Console Next Month

Quick Match, Rainbow Six Wiki

Does Rainbow Six Siege have crossplay? — SiegeGG

Epic Games Store 2021 Year in Review - Epic Games Store