With all do respect SuperHero, I completely agree that they should reconcile if possible given they have a child. However, if things aren't working out then he should know what his options are for divorce and I would most certainly try and keep the divorce in New Zealand and not India. He will go through hell if wife and child run to India and she initiates divorce there.
Mr. Hidden, you can read about divorce process in New Zealand here: https://www.justice.govt.nz/family-justice/separation/divorcing - you will need to be separated for two years and the court will need to be satisfied that adequate arrangements have been made for the caring of children.
I would suggest that it is your best interest to have yourself, your wife and your child in New Zealand first and try to reconcile. If that doesn't work, then separate in New Zealand and apply for divorce and make the proper child care arrangements. Further, is your child a "New Zealander" (NZ passport & born in NZ) or Indian? If the former, once your child is in New Zealand, you can ask the court for an 'Order Preventing Removal' to stop your wife from taking your child to India if you fear this can happen (read more here: https://www.passports.govt.nz/Preventing-Children-Being-Taken-from-New-Zealand#prevent)
Speak to a lawyer in New Zealand to confirm what the best options for you are.