I do not know.

We have been using RackAFX 32-bit DLLs as VST2 and VST3 without issues for the last 2+ years, in Reaper, Cubase, Sonar, Ableton Live, etc...

We have been compiling and using 64-bit VST2/3 plugins via [Make VST} without issues for the same period of time, using Reaper, Sonar, and Ableton Live 64-bit versions.

Tom Beer, my moderator who suggested that you step back and become more familiar with C++ and Visual Studio before attempting to work with plugins, has personally tested 32 and 64 bit versions on a wide variety of hosts without problems:

Tom's exhaustive testing also gives us several more validated VST2/3 clients:

Cubase 7.5 64 bit
Cubase 8 Pro 64 bit
WaveLab LE 8 64 bit
StudioOne 2.5 64 bit

tested configurations:
RackAFX-Dll (VST2) works via the native bit-bridges as well as jBridge
MakeVST-Dll 32bit works as VST2 via native bit-bridges as well as jBridge
MakeVST-Dll 64bit works as both, VST2 and VST3

WaveLab LE 8 32 bit
tested configurations:
RackAFX-dll works as vst2 and vst3
MakeVST-dlls work as vst2 and vst3

Brainspawn Forté 3.2.20 64 bit
all 32 and 64 bit VST2 dlls as native 64, pre-jBridged and on-the-fly jBridged (forté uses jBridge as its "native" bit-bridge and optionally as 64-to-64 bridge for process-separation of plugins to prevent crashes)

Fruity Loops 11 64 bit
MakeVST-Dll as Vst2 32 bit (native bridge) and 64 bit
MakeVST-Dll Vst3 64 bit

I also suggest that you stop working on VST plugin development until you are very proficient in C++ and Visual Studio and software-compiling in general.

- WP