Sure. Max thrust for ambient conditions may be produced at 96% N1 or 102% N1, or something in between (or slightly more or less). "Red line" N1 is a fixed value for an engine, regardless of ambient conditions, such as 117.5% for the GE CF6-80C2 or 111.4% for the PW4056.
Therefore you can "overboost" the engine without exceeding "red line" N1.