The latest version of Office you can run on the 68K is 4.2.1 (Word 6.0, Excel 5.0, PowerPoint 4.0). But this is widely known as being a slow, buggy, wretched version. Office 98 was much better and fixed most of the problems of the previous version, but it requires a PowerPC.

You might be better served, particularly if you don't need all of the Office programs, with slightly older versions of the individual applications, like just Word 5.1.