Brennan is the English form of two Irish Gaelic surnames:
Mac Branáin (bran, raven) "MacBrannan" of Mayo-Sligo-Roscommon.
Ó Braonáin O'Brennan of Kilkenny
The Irish spelling is Ruairí; the Scottish spelling is Ruairidh.
The spelling in Scottish Gaelic is A' Mhòr Bheinn.
No Gaelic version.
You don't. Cheyenne is a non-Gaelic, proper name and, as such, has no Gaelic spelling.
calin is not a Gaelic spelling.
The Scottish Gaelic spelling is Eòghan.
If that is the correct spelling, it is not Gaelic.
Conehar is not a Gaelic spelling. Is it a surname?
The Scottish Gaelic spelling is Steaphanaidh.
The Scottish Gaelic spelling is Steaphanaidh.
It really doesn't have a Gaelic equivalent.
In Scottish Gaelic it is spelled Mòrag.