"Should harmful contact (tackling/ scrum) be banned in rugby for 11-18 year old's?"
Is this meant to be a serious question.
It's like asking "when did you stop beating your wife?".
The question should be "Should contact (tackling/ scrum) be banned in rugby for 11-18 year old's?". Throwing in a loaded adjective like "harmful" is not a good design of a question. I hope your Supervisor pulls you up on this.
Of course I think harmful contact should be avoided. Who doesn't? That is why it is best that children are taught how to tackle/scrum properly, so that it is not harmful.
Crossing the road is potentially harmful - do we keep our children away from roads or do we teach them how to cross safely? The same applies here.