Can microsoft office be used on an iPad pro

Yes. The apps can be downloaded from the App Store individually (i.e., search for Word, Excel, etc).

Also note the following from the App Store listing:

To create or edit documents, sign in with a free Microsoft account on devices with a screen size smaller than 10.1 inches.

Unlock the full Microsoft Office experience with a qualifying Office 365 subscription for your phone, tablet, PC, and Mac.

There is no complete MS office suite, but the individual applications (Word, Excel, Outlook, etc.) are available. Also, there are several alternate apps available as well.