Ingredients : 
Carbonated Water, Sucrose, Glucose, Citric Acid, Taurine, Sodium Bicarbonate, Magnesium Carbonate, Caffeine, Niacinamide, Calcium Pantothenate, Pyridoxine HCI, Vitamin B12, Natural and Artificial Flavors, Colors.

100% Halal ,taurine found in Red Bull drinks are halal. This is because the taurine in Red Bull drinks is not derived from animals, it is produces synthetically (source).