Your question is completely valid, especially given that you are not a NSW HSC student and are looking to study in a country other than the one where you are finishing school.
Essentially, with the maximum ATAR being 99.95, an ATAR of 96 can be classified as being on the more difficult and demanding end of the spectrum. This means that, in order for a NSW HSC student to achieve an ATAR of at least 96, it is preferred that they achieve HSC results in the band 6/E4 region across their subjects. A band 6 is a mark of 90 and above (out of 100) and a band E4 is a mark of 45 and above (out of 50).
In terms of the results in the New Zealand NCEA that would be considered as equivalent with an ATAR of 96, in addition to the importance of taking at least 80 credits at level 3, at least 50 of those would need to be endorsed with Excellence (the higher this number, the higher the chance of being made an unconditional offer). From what I have observed, it seems that results of this standard would place you in a good position and will hopefully give you a good chance of converting your conditional offer into an unconditional one.
I hope this helps!