Brought to trial means that the particular case or trial has begun. For example, if a grand theft auto case is currently being tried, it is said to have been brought to trial. This term refers to all different types of cases. Any case that has begun being tried is said to have been brought to trial.
Brought to trial is basically a formal way of saying that the case has begun. The usual point where one would say that the case is brought to trial is when the first witness is sworn in. Many defendants have to wait weeks, months, or even longer to have their cases brought to trial. However, the waiting period is necessary in order to make sure that they receive their day in court.