Currently, the XCTU supports the following operating systems:
* Microsoft Windows XP/Vista/7/8/10 (32 and 64 bits)
* Mac OS X, 10.6 and higher versions (only 64bits)
* Linux (32 and 64 bits)
As you can see, for version 6.3.12 there is Windows 10 support in 32 and 64bit mode.