A conversation about course choice is easier when it starts with the actual program. New Zealand's official study and immigration websites describe courses and the government's genuine intentions requirement. An admissions interview and a visa assessment remain separate steps.
Know the course you selected
Read the provider's course information and note the qualification, main subjects, duration and location. Check the education organisation through the NZQA search where relevant. If a detail is unclear, ask the provider rather than guessing.
Explain your own connection
Describe how the course fits your prior study, work or interests. If you are changing direction, explain what led to that decision and what you expect to learn. A specific answer can include a course component that matters to you and a realistic question you still have.
Use the government page for current visa information
Immigration New Zealand explains that student visa applicants must genuinely intend to study and meet their visa conditions. Its current guidance describes the information considered. Use that source for visa requirements, and the provider's own information for the admissions conversation.