From what I’ve heard from their music and read when researching:
Vocal line: Jimin, Jin and Jungkook are tenors. Taehyung is a baritone.
Rap line: though they rarely “sing”, we could say RM is a baritone also… Hoseok a tenor… Yoongi is difficult, I would say bass, based only on personal perception.
Hope this was useful. Have a nice day!
