– If the installer asks, select "64-bit" (some packages auto-detect your OS).

: Additional files for different regional support. Why Choose the 64-Bit Version? Microsoft Supporthttps://support.microsoft.com

Whenever possible, it is safer to download Office 2016 directly from the Microsoft Services & Subscriptions page if the product is already linked to your Microsoft account. Conclusion

No. Microsoft does not support cross-architecture upgrades. You must uninstall 32-bit Office fully, then install the 64-bit version.