You will have to apply for a new visa to replace the current one. Also at the time of lodging a new visa application, you will not have already spent a total of nine months over the previous 18 months. That means you may only spend another 3 months in New Zealand once you get the new visa.
How can I stay in New Zealand for over six months as a visitor visa holder?
My daughter is a permanent resident of New Zealand. I am a Chinese citizen. I entered the country four months ago with a visitor visa. I understand that I can’t stay for longer than six months as a visitor. However, due to the outbreak of coronavirus in China, I was hesitated about traveling back. Is there any way I can extend my stay in New Zealand without leaving an overstay record that could impact my visit to the country in the future?
You can apply for another visitor visa, as any visitor to New Zealand can stay for nine out of 18 months in the country. However, if you already stayed for nine out of last 18 months, you can only apply for an additional visitor visa and ask for consideration. I suggest that you consult with an immigration adviser regarding this.