To study in New Zealand, you have to apply for a student visa. You can apply for a New Zealand Student Visa after receiving a formal offer of place from the institution.

Application fees for New Zealand Student Visa is US $150 (equivalent to Rs. 6,400/-)

Document Checklist to lodge a student visa application

Student Visa Application Form and Supplementary information form
Passport (Passport should be valid for completion date + 3 months)
Photograph (Passport sized photograph affixed to application form)
Demand Draft for Visa Application Fee
Covering Letter[1]
Offer of Place
Guarantee of Accommodation
Financial Documents – Funds to cover:
Tuition for First 12 months of study
Living Expenses for 1 year (NZ$10,000 per annum)
Plan of payment with evidence of access to funds to meet the tuition for remaining period of study and living expenses
Academic Documents
IELTS Score Card
Evidence of Employment (if applicable)
Health Requirements[2]
Police Clearance Certificate[3]
[1] Covering letter should include your background covering the evidence of funds, your English language ability (IELTS Score) and Statement of Purpose hand-written by you. Statement of Purpose should address questions like why you are applying for the visa, why you wish to do the course and how the course would help you in future.

[2] Health Requirements:

If you have an offer of place for a course with duration between 6 to 12 months, you must undergo a TB screening X-ray and submit Temporary Entry X-ray Certificate form (NZIS 1096) along with associated medical reports and X-ray.
If you have an offer of place for a course with duration more than 12 months, you must undergo a full medical and x-ray examination and submit Medical and Temporary Entry X-ray Certificate form (NZIS 1007) along with any associated medical and laboratory reports.
[3] All students above 17 years of age and intending to stay in New Zealand for more than 2 years must provide a Police Clearance Certificate. For Indian students, Police Clearance Certificate has to be obtained from the Regional Passport Office or Office of Deputy Commissioner of Police.

Processing Time for Student Visa Application
The processing time for student visa application depend on the application and can vary from 15 to 90 working days.

Student Visa applications are categorized into Positive Profile category “A” Applications, Positive Profile category “B” Applications and other Student Visa Applications depending on the risks perceived in the application by the visa officer. Visa application processing times for these categories are as below:

Positive profile category “A” applications – 15 working days
Positive profile category “B” applications – 30 working days
Other student visa applications – 75 to 90 working days
Factors used to determine if an application can be categorized as Positive Profile are:

Good Academic Record
IELTS Academic Test Score of at least 5.5
Immediate family’s verifiable evidence of funds to meet the educational and living expenses in NZ – including paper trails to explain any recent large deposits in accounts;
Regular source of sufficient income of financial guarantors;
Intended course of study relevant to qualifications and/or work experience
Career progression opportunities
Clear health & character requirements
In addition to the above factors, to be categorized as a Positive Profile Category “A” Applicant, you must have:

An overall score of 6.5 or above in IELTS Academic Test
Offer of Place to study a course which is at NQF Level 7 or above
Visa Application Approval in Principal
Once all the visa documentation requirements are met, the New Zealand High Commission will advise you that the visa application has been approved in principal. For the visa issuance, the following have to be submitted within 1 month of getting the Approval in Principal:

Fee Receipt issued by New Zealand Institution towards payment of tuition deposit for the 1st year of study.
Any other documents suggested by the High Commission.
Visa Issuance would take at least 5 working days after the above documents are received at the New Zealand High Commission.