Do I need New Zealand Electronic Travel Authority (NZeTA) if I am transit passenger through Auckland International Airport?

Yes, but you must be a citizen of either Visa Waiver country or Transit Visa Waiver country.

Transit passengers must remain in the transit area at Auckland International Airport.

If you need to leave the Auckland International Airport, then you must either apply for a New Zealand Visitor Visa or passport holders of eligible countries need to apply for New Zealand eTA and pay the Tourist Levy fees.