On https://github.com/red/red/tree/master/bridges it says not implemented, will it be ?
Please read the official news before raising such questions (or rather consider to use Gitter community chat).
Android bridge is currently developed in a private branch and will go public in 0.7.1 release.
.NET bridge in the master branch is a PoC; there are Mono bridge and .NET bindings available from community members, but official CLR support, as far as I know, is not planned in the near future, and will likely take a high priority in post-1.0 roadmap.