The teenager drowned at an orientation camp in the North West last week and his body was later found in the Crocodile River.
The commission said it approached Mpianzi's family after reports of his death.
It said the meeting was to determine how the commission could help the Mpianzi family to find justice.

At the same time, Parktown Boys' High has suspended its academic programme for Monday after the death of the grade 8 pupil under questionable circumstances.
North West police and the Department of Education in Gauteng have launched investigations into his death.
The circumstances around Mpianzi's death are still sketchy with very few details about the preventative measures the school and the Nyathi Bush Resort in Britz took - if any.
The grade 8 pupils were due to start their academic programme on Monday but the school has suspended classes saying it expected the day to be challenging for the boys.

One father of a grade 8 pupil said he was worried about how his son was going to cope in the wake of the tragedy.
“It really bothers me; they had counselling because it’s traumatic. One of their own was left behind.”
The boys will convene for assembly on Monday morning and then they will be addressed by a trauma counsellor.
The school said during the course of the morning, a counsellor will be meeting with all the boys and staff.
School will end at noon on Monday and all cultural activities and sport have been suspended.

Source: EWN