depends on if ur neice is your brothers child if so the he would be the grandfather but if u have another brother then he would be its great uncle! ..
The daughter of your brother is your niece.
Your son and your niece are first cousins. Your son and your niece's son are first cousins, once removed. Your grandson, or granddaughter, and your niece's son are second cousins.
your cousin
Are you asking what you call your brothers daughter? Well if you are your brothers daughter is called your niece.
Your niece's son is your great nephew.He would be your grandnephew
Your son and your niece are first cousins.
Your brother would be your son's daughter's great uncle and your son's daughter would be your brothers great niece! Hopefully that makes sense :)
Great niece
Your niece's son's daughter is your great grand niece. Your niece's son is your grand nephew or your great nephew, whichever term you prefer.
If your niece's is by your sister but the brother is by your sisters new husband & another woman there would be no blood relation. If not then he's the nephew
Your son and your niece are first cousins to each other. Your son and your niece's son are first cousins, once removed.
your step niece,,, if it was your brothers own daughter it would be your niece, since its his stepdaughter, than its your step niece.