Many languages distinguish between inclusive and exclusive first-person plural pronouns (“we”). (Click or tap here to see more details)
The inclusive “we” specifically includes the addressee (“you and I and possibly others”), while the exclusive “we” specifically excludes the addressee (“he/she/they and I, but not you”). This grammatical distinction is called “clusivity.” While Semitic languages such as Hebrew or most Indo-European languages such as Greek or English do not make that distinction, translators of languages with that distinction have to make a choice every time they encounter “we” or a form thereof (in English: “we,” “our,” or “us”).
For this verse, translators typically select the exclusive form (excluding the congregation of the disciples).
In some languages, including Chichimeca-Jonaz, Tepeuxila Cuicatec, or Huautla Mazatec, however, the translators selected the inclusive we.
Source: Velma Pickett and Florence Cowan in Notes on Translation January 1962, p. 1ff. and Viola Waterhouse in Notes on Translation August 1966, p. 86ff.
W. R. Hutton (see The Bible Translator April 1953, p. 86ff. ) who worked on the translation into Karbi says this: “In Acts 6:3 a matter of church government comes up. The Revised Standard Version has ‘whom we may appoint to this duty.’ Does the ‘we’ include those who do the picking in the first place as well as the Apostles? It is very likely the answers here will diverge along the lines of church polity and Baptists give one answer and Church of England folk another. It would be convenient not to have to take sides in a translation but for those of us who have an inclusive and an exclusive ‘we’ a decision has to be made.”