I am used to previous versions of NDK builds which came in zip format. I downloaded the recent r10 version for windows which had a .exe version. The exe version is
r10
Android Studio 2.2 installs it in C:\Users\[username]\AppData\Local\Android\Sdk\ndk-bundle (on Windows 10).
C:\Users\[username]\AppData\Local\Android\Sdk\ndk-bundle