Call the Clerk of the Court in the county where he is being sentenced, either on the day of the hearing or the day after. The clerk's office maintains the official record of all court proceedings and outcomes, and once the hearing is on the books, the information is public record. You do not need to be present at the hearing or have any special standing to request it. Just give them his full legal name and case number if you have it, and they can tell you what was ordered.
Many courts also have online case lookup systems where you can search by name and pull the docket yourself without calling. Search the court's website for the county where his case is filed and look for a case management or public access portal.
His attorney is another source. If he has representation, reaching out to the attorney's office after the hearing is a direct way to get a clear explanation of the sentence rather than navigating the court records system on your own.
If he calls after the hearing, that will likely be your fastest update. Have phone funds ready and keep your phone available around the time the hearing is scheduled.