Diploma

For MBA, you should have a graduation in any field. UG Diploma is considered equivalent to class XII.

Hello Shanaya,
You have completed diploma in computer science and now you want to have career in 'Interior Design "? See, what we study after 10th many a times is normally what our parents wants us to do. But let me assure you that there are many shining example when students have not touched engineering after completing it but became highly successful in their other chosen field. If you feel passion for ID, then just go ahead. Don't worry.

If you score good marks in common entrance test, then you can get admission. Even if you have reservations, then yes you will get admission.

You can do this Diploma course in New Zealand.
After one year study, you will get one year work search visa. In getting a job, you will get 2 year work visa and you can apply for PR.