Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Red Bull drink is considered amongst the famous drinks that add energy to the drinker. It is widely used by sportsmen, to strengthen their energy to play and do well in competitions. We cannot give a ruling that this drink is free from alcohol or not, because we do not know the reality. However, we advise the brother asking the question to read the label or to go to a factory of analysis which is trustworthy to find out the reality, and if he is informed that this drink contains alcohol, then it becomes Haram.
Allah knows best.