Ring the school?
There is a certain percentage you must not fall under in absenteeism. The school should know the percentage requirement + your son's. Your son should also be able to prevent the n-awards becoming n-determinations - ring school about this as well.
Also, your son should know all this anyway - my school had frequent meetings (like over 5) about n-awards, n-determinations, and the very real possibility of repeating year 10 / not going onto year 11. 2 people in my grade could not go onto year 11.