So, to answer your question: you must wait until you meet all of the requirements in my post above before you may apply for the grant of New Zealand citizenship.
For most people, the presence requirement is of most concern. Someone who never travels outside New Zealand will meet the presence requirement precisely 4 months and 240 days from that person's first day in New Zealand as a resident. It is important to note that
any travel outside of New Zealand may mean a longer wait until the presence requirement is met (this depends on the individual periods of absence -- see the examples provided by the Department of Internal Affairs
here; expand the "If you are not sure you meet the requirement" section to view them). Also note that as per the
Citizenship Guidance Document, the presence requirement is calculated as of the date you lodge your application.
It is of course possible to meet the presence requirement but not meet one of the other requirements (from people posting on the forum, usually it will an issue with character). Again,
all requirements above must be met.