However Mr Te Rangi says O'Sullivan has no authority to call a meeting and said the doctor's actions were "autocratic" and not fitting to the board of the Te Whanau O Hato Petera Trust.
"The recent attempt by you and your faction to ambush and reconfigure the office of the Chair of Te Wh?nau o Hato Petera Trust committee is profoundly disappointing on a personal level as well as an institutional one," Mr Te Rangi said.
"Your actions threaten to bring into disrepute the religious and historical foundations of Hato Petera College along with our Tupuna."
"Whilst it is tempting to acquiesce to your will for the sake of peace and tranquillity, I am reminded of my responsibilities and obligations as chair and upholding the dignity and mana of this post."
The board is supposed to have 12 members. It currently has six.
Mr Te Rangi said he would continue to hold his position until it could be discussed at the special meeting.
Dr O'Sullivan, who has been named New Zealander of the Year and Maori of the Year, says Northcote's Hato Petera College has failed to act appropriately on safety.
He told Radio New Zealand this morning there had been a backlash but some board members were offering support.
"I'm certainly getting attacked, that's for sure, but it's not new to me.
A lot of people want to keep things in the dark.
"[The board] hasn't ensured these allegations are being looked at...and I'm not prepared to sit on my hands anymore, to be quite frank."
Two of Dr O'Sullivan's seven children board at the school and he is an old boy who has been on the school's board for eight months.
Conversations he had with children at the school recently showed there were "things happening on the ground" affecting the youngsters, he said.
He did not want to discuss the bullying allegations because some of the cases might go to court, Dr O'Sullivan said.
"I just don't believe that at the moment I can put my hand on my heart and say these kids are going to get the support they need...I'm not just a Johnny-come-lately that's rocking the boat. I have been concerned for a good part of those months [on the board], there needs to be strong governance.
"This school is coming up 100 years and it's put out some amazing leaders. I believe it has that opportunity to be that great school of glory again."
Police confirmed this morning they had received a report relating to an incident at Hato Petera college and investigations were underway to determine whether any criminal offence has occurred.
The Herald reported in April about issues at the school, including the roll falling below 100, dilapidated buildings, bullying, infighting and a lack of confidence from its owner, the Catholic Church.
Two other incidents in the last 12 months - including one where a child had been hit with a stick - had also been referred to police.
Hato Petera, whose former pupils include All Black Walter Little and the late artist Ralph Hotere, is the sole remaining Maori boarding school in Auckland and one of only six in the country.
Two other such schools, St Stephen's and Queen Victoria, were closed in the early 2000s.
There have been ongoing issues at the school between the board, the school, the ministry of education and the church in terms of who will pay for the upkeep of the hostel buildings.
A treaty of Waitangi claim made against the church and Crown by members of the wider school community have led to further tension.
