Guess what? Today we're introducing the Greek "indefinite pronoun" -- "someone," "anyone," "anything," and the like. The form tis functions for both the masculine and the feminine -- meaning either "any man" or "any woman." (It can also be gender-neutral: "anyone"). In 1 Tim 3:1, Paul uses tis.
Please note it's not the gender of tis that shows that an overseer must be male. The gender is unclear apart from the broader context. Every adjective used in Paul's list of qualifications is masculine. Moreover, the use of the expression "husband of one wife" in verse 2 proves that men are being referred to. In addition, we find no female elders in the New Testament.
Once again, here's an instance where Greek grammar per se doesn't necessarily require a particular interpretation. As I like to say to my students, "Greek doesn't require; it permits." The context must never be ignored.