Hi,
NZ currently only accepts degrees similar to theirs (4 yr BSc (Hons))for application.
If you graduate with the typical British 3 year degree, this means, that you will need 1 year work experience or further study to be accepted for the application process.
As to the exams: I understand that you will be assessed and you only have to do an exam if you do not meet their criteria in the three core physio areas.
I don't actually know anyone who has ever sat an exam in NZ.
Regards,
Fyzzio