Can part time job will cover all the cost in New Zealand? How much fee structure can be covered with part time job?

Dear Bibek, I am sorry to say that it is a fallacy that part-time work can cover the cost of tuition and stay for international students. At the best it can defray a small part of the cost or provide you with some extra pocket money for your personal use. The most important part to remember is that

if you take up Level 7 diploma program the cost of tuition fees will be around 7.5 lakhs in any colleges in New Zealand. You will have classes only two days in a week and you are legally allowed to work 20 hours part time per week. if you share your room with other students and do your own cooking