Is this correct possessive pronoun?
My brother owes money and he refuses to pay back MINE (Possessive pronoun)
2 answers
Yes. Both MY and MINE are possessive pronouns.
I don't think the second half of your sentence makes sense.
... he refuses to pay back ______.
The sentence here is better:
http://www.jiskha.com/display.cgi?id=1278523390
... he refuses to pay back ______.
The sentence here is better:
http://www.jiskha.com/display.cgi?id=1278523390