The Verdict: Not eligible
You have no descent claim, because New Zealand citizenship by descent comes only from a parent who was a citizen when you were born. Look at the skilled migration, partner or investment routes to residence instead.
A grandparent or earlier ancestor gives no claim, and New Zealand has no ancestry visa. This is where it differs from the United Kingdom and Ireland.
Check one thing first. A parent born in New Zealand, the Cook Islands, Niue or Tokelau before 2006 is a citizen even if they never held a passport. A parent born abroad to a New Zealand parent is a citizen by descent even if never registered. If either describes your parent, go back and answer yes.
Otherwise the way in is residence first, then citizenship by grant after five years holding a residence class visa.