How to boxing, kickboxing right uppercut or #6 punch
The right uppercut is a power punch but it is very short so it is used primarily as a way to make space while your opponent has you against the ropes. You can use it to lift the head to set up for the #3 or left hook. [Remember that there are tonnes of different combinations and I am only giving you some very fundamental basics to get you started.] Using the left shoulder to push him off then turning and lifting the 6 can give you the opportunity to slip out to the right and shove him to the ropes as an example.
The main points for throwing a good right upper-cut are:
1. Push and turn off the back foot.
2. Translate that turn through the entire body until the left shoulder is pointed behind you, rotating the right shoulder on the axis of your spine, keeping your head to the right of your opponent.
3. Connect with the chin, try to lift his head from inside his guard.
4. Bring the hand back to the face.