Can I use TLS 1.2 or 1.1 (if 1.2 is not available) in .net when calling a web servivce?

I would like to be able to use TLS 1.2, if a web service requires it, but also (for the time being) make calls using TLS 1.1 to services that do not support it.

Currently we are using ServicePointManager.SecurityProtocol to set this in our code. (.net 4.0) Is this already backwards compatible? Or is it an all or nothing thing? And if so, is there some way to OR things together?