The only reason to stick with the 32-bit version of Office 2016 in today's world is if you rely on very old third-party plugins (add-ins) that have not been updated for 64-bit architecture. If you are unsure, 64-bit is almost certainly the right choice.
While the 32-bit version was once the standard for compatibility, the 64-bit version is now preferred for modern systems. Choose between the 64-bit or 32-bit version of Office download office 2016 64 bits