If my brother was violated for dirty urine and his probation officer put out a warrant for him, how long will he do if he turn himself in?

He could do up to the original amount of time that he was facing initially. It is very serious and he needs to get an attorney with decades of experience.

The sentence he receives will depend on a lot of factors such as the judge, the prosecutor, the underlying case, any prior violations, prior criminal history, and some others. I recommend you contact a local defense attorney who can review what has happened in his case and who knows the layout of the criminal justice system in that community. Without more background and facts regarding what has already happened in the case there is no way of really predicting what he may get.