Check the Document Language Settings While Word Online doesn’t offer comprehensive language settings, you can still set the document's language to Arabic before uploading it. Sometimes, setting the language and regional formatting in the desktop version can help retain the number formatting once it's uploaded to OneDrive—though keep in mind, this may not work reliably in Word Online.

Adjust Browser Locale Settings Another option is to change your browser’s locale settings to Arabic. In both Google Chrome and Edge, you can add Arabic as a preferred language. This may influence how some content, including numbers, is displayed in Office Online.

Try Embedding Fonts or Using Field Codes If you’re preparing the document offline, you could experiment with embedding fonts or using field codes to display numbers in Arabic (Hindi). Be aware, though, that these methods might not carry over consistently when you open the document in Word Online.

Reach Out to Microsoft Support Since this limitation is a known issue with Word Online, contacting Microsoft Support could be helpful. They may have specific solutions or SharePoint add-ons that can enable better customization in your setup.