I'd go with Peter's idea, unless it is very obviously BRR.
My wife's gg-grandfather has his place of birth on the census and FMP has it transcribed as Yorkshire, England when it was clearly something beginning with a Y in Ireland. Putting a few variations of what the word looked like into Google got a redirecting to Youghal in Cork.
Record keepers seem to struggle with the accent of Irish immigrants, especially when it comes to unfamiliar places (or names - I have my wife's surname recorded 14 different ways. Even with Barnes, the records give us 50/50 Barnes/Barron or Baron).
If it definitely BRR, then it may be an acronym, perhaps with the B being British. However, Googling "BRR Ireland" leads me to Birr in Offaly so....