Given that the familiar form of .NET is run on Windows, which is not a real-time O/S, and MONO runs on Linux (standard kernel is also not a real-time O/S).
Given als
Short Answer: No.
Longer answer: The closest you can get is running the .net Micro Framework directly on Hardware, but the TinyCLR still doesn't give you deterministic timings. Microsoft has Windows CE/Windows Embedded Compact as their real time offering, but even that is only real time for slower tasks (I believe somewhere in the range of 50 microseconds or more - not sure if that qualifies for Hard Real Time)
I do not know if it were technically possible to create a real-time c# implementation, but no one has done one and even .net native isn't made for that.