He can discuss his options with his attorney. He should be in front of the judge within 2 days of his arrest. From there, it depends on how his issues are resolved.
He'll face a judge to answer to probation violation allegations. For any violation, they have to prove that it was a willful violation, meaning he had the ability to do what the court ordered, but didn't. I know it's too late to turn back the clock, but it's always better to seek an extension before the due date, rather than miss the date, especially if it results in a warrant. If he is unable to pay, the court may convert some of his fines to jail time and/or community service.
If the judge determines it to be a violation of his probation he theoretically could be held for the remaining senatnce of his case. Assuming that this is a first time DUI it could be 6 months less any time he has already spent in jail on this case. In realtity what most judges will do is hold him for the amount left to pay off all the remaining fees and fines; which is typically 13 days or less depending upon how much he has already paid.
depends upon where he was arrested and what for. 72 hours is usually the maximum he can be held without being taken bedfore a magistrate or judge. Most jurisdictions claim that excludes holidays and weekends. The penal code and constitution say "without delay" . Have the jail do an OR workup for him. If arrested in county where the warrant is issued he will be taken before a judge and should get or ask for an appointed attorney. I in another county they will take before their own judge or rellease him.