At the moment, no resident can sponsor ANY family-members apart from their partner and dependent children. A recent decision by the NZ government has closed the parent-category sponsorship option for at least two years - before that, you had to have held a Residence visa for three years to be eligible, and there were other, strict, requirements. See here.
https://www.immigration.govt.nz/new-...-resident-visa Other relatives are not admitted just on the grounds of family relationship, but would have to qualify for a visa in their own right, for instance, as a student, or as a skilled and qualified worker.