Scholarships are a great way to support you financially in your studies and New Zealand provides a range of government, private and university funded scholarships to undergraduate and post-graduate international students. It is undeniable that scholarships are highly competitive but you can always increase your chance of getting the scholarship by finding the ones matching your qualification and rigorous preparation. Some scholarships consider factors such as country of origin, area of study or leadership potential so you need to find that is best suited to you.

Some of the Government funded scholarships available to Nepalese students wishing to study in New Zealand are:

New Zealand Development Scholarships

This provides scholarships to candidates from selected developing countries including Nepal an opportunity to gain knowledge and skills through study in specific subject areas which will assist in the development of their home country.
New Zealand Development Scholarships

New Zealand International Doctoral Research Scholarships

This is a prestigious and highly competitive scholarship that aims to attract and retain the best international researchers to New Zealand. The scholarship provides full tuition fees and a living stipend for up to 3 years. 
NZIDRS

Some other scholarships are University-specific. For this you need to check with the universities, prepare thoroughly for the application and apply in time. 

New Zealand Education | Scholarship Page