There's no way to answer your question because there's no "usual" sentence.
The outcome depends on many different factors, including the exact charges, whether they are felonies or misdemeanors, whether the victim was injured, and the overall circumstances of what happened. There is no way anyone can predict what might happen without this information.
Your brother in law needs a lawyer. If he can't afford one, the judge will appoint one for him when he goes to court.