You must
be aged 17 years or younger
be aged 18 to 24 years, and have no children of your own.
And
be born or adopted before your parents applied for residence, and have been declared on your parents’ application for residence
And
be single (i.e not in a partnership)
be in good health
be of good character
If you are aged 21 to 24 years you may be asked to provide evidence that you are dependent on an adult for financial support.
Evidence that parents are lawful New Zealand residents can include the original or certified copies of:
a current New Zealand residence class visa or residence permit or Returning Resident’s Visa in their passport or travel document