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, the Karbi translation uses the exclusive pronoun, since “Paul has been arguing strenuously for the inspiration of himself and his assistants or fellow preachers and here God has graciously revealed more to them than to others.” (Source: W. R. Hutton in The Bible Translator April 1953, p. 86ff. )
SIL International (1999), however, recommends the inclusive form, referring to Paul and the Corinthian Christians. This is what the Tok Pisin translation also chooses.