An Indian citizen becomes an NRI if he fulfills the conditions mentioned below. These criteria are set out by FEMA (Foreign Exchange Management Act).

1. He stays outside India for more than 182 days during the preceding financial year, between April 1 to March 31.
2. An Indian citizen leaves India for the purpose of employment, business, education, stay with parents/ children, with the intention of staying abroad for an uncertain period. In such cases, he becomes a NRI the moment he leaves India, even if he has not stayed abroad for 182 days or more during the financial year.

The university will use your year 12 results that you received abroad for admission, which is another reason you wont be considered a local candidate. So if you did study year 12 abroad, you will be considered as a NRI candidate for university admission purposes.