In modern Greek it could be transcribed as Mπρυν or Mπριν. In ancient Greek Βpιv would be closer.
In ancient Greek, at least in the classical period (until, say 323 BC), the letter beta, Β, would have been pronounced like English "B," but sound changes during the Roman period transformed the pronunciation to something like English "V," and in modern Greek, the only way to represent the sound of the English letter B is "Mπ."
In classical Greek, the letter upsilon, Υ υ was pronounced first like English u (or to be more precise, like French ou), then later like French u. In the Roman period the pronunciation changed to a sound similar to French i, and remained that way down to modern Greek.