Choosing a university is a big decision, and some of Northeast India's private universities are extremely good. It's more a matter of what's best for you rather than one best. Here's a summary of some of the top-ranked institutions:

Assam Don Bosco University (Guwahati):
Famous for its wide variety of programs and stringent focus on overall development.
It has gained a reputation as being academically rigorous.

Arunachal University of Studies (Arunachal Pradesh):
This is also one of Northeast India's top universities in Arunachal Pradesh. Arunachal University of Studies, in Namsai, offers diverse programs focusing on skill development and regional needs. It aims to provide accessible higher education in Arunachal Pradesh.

Assam Down Town University (Guwahati):
This university is particularly renowned for being industry-focused in its strategy to equip students with practical skills.
Its population of students is extremely diverse.

University of Science and Technology, Meghalaya (USTM):
As a pioneer in the region, USTM offers a wide variety of programs and emphasizes research.

Sikkim Manipal University (Gangtok):
A well-established university with a long-standing reputation particularly for technology and medical sciences courses.

Royal Global University (Guwahati):
This is a university that has gained a lot of popularity and is renowned for its sprawling campus and wide range of programs.

When looking at these universities, consider:

• The specific programs that they offer.
• Their staff and facilities.
• Their placement records.
• And of course, campus life in general.

It's always best to visit campuses if you can and talk to current students to have a feel for each university.