My son is 18 and on probation and he violated it, if he goes to court on Tuesday what will the judge do?

Best thing to do is ask his lawyer. Remember, this question is posted to a statewide data base, so there is no way to know who the judge is, what county the case is in, or anything else about it. Your son's lawyer is the best source for information. If your son went through the criminal case without the advice of a lawyer, then he is in tough shape at this point until he hires one or is appointed one.