windows 10 mobile wiil only support 32 bit operation .check Hardware specifications on wiki .
Clearly listed : -
Hardware specifications :
Minimum specifications for Windows 10 Mobile devices are similar to those of Windows Phone 8, with a minimum screen
resolution of 800x480 (854x480 if software
buttons are in use) and 512 MB of RAM.
Owing to hardware advancements and the
operating system's support for tablets,
screen resolutions can now reach as high as
QSXGA resolution (2560?2048) and further,
as opposed to the 1080p cap of Windows
Phone 8. The minimum amount of RAM
required is dictated by the screen's
resolution; screens with a resolution higher
than 960?540 require 1 GB of RAM, screens
of 1440?900 and higher require 2 GB,
2048?1152 and higher require 3 GB, and
2560?2048 and higher require 4 GB.[47]
As with Windows Phone, Windows 10
Mobile supports ARM system-on-chips from
Qualcomm's Snapdragon line, adding
support for the 208, 210, 615, 808, and 810.
The operating system will also introduce
support for IA-32 system-on-chips from
Intel and AMD, including Intel's Atom x3 and
Cherry Trail Atom x5 and x7, and AMD's
Carrizo. Although some of these supported
chips are 64-bit, Windows 10 Mobile will
only support 32-bit operation.[47]
check below :
https://en.m.wikipedia.org/wiki/Windows_10_Mobile