Is DTU tier 1 or 2 or 3 college?

Yes, DTU is a Tier-1 college. The engineering institute has been ranked 29th position among the top engineering colleges in India by NIRF. This can be justified with the following reasons:

• Reputation: DTU has a strong reputation for engineering and technical education. This institute ranked 29th among the top engineering students of Delhi. DTU was ranked 2nd by Times Engineering Rankings 2021 and achieved 7th position in India Today’s Best Engineering Government Colleges survey for 2021.
•  Flexible learning: Through initiatives like MOOC and SWAYAM, DTU also makes sure that students learn the fundamentals of education.
• Notable alumni: Vijay Shekar Sharma (founder of Paytm), Suhail Sameer (CEO of Bharatpe), and many more eminent personalities are notable alumni of this organization. 
• Placement Opportunities: DTU has a proven track record of placing its graduates in prestigious companies both domestically and abroad. The maximum package available from DTU was INR 1.8 CPA, while the average package was INR 15.16 LPA. 

Therefore, from the perspective of engineering and technology education in India, you can categorize DTU as a tier 1 college. However, it's crucial to remember that a college's perceived standing or tier might be arbitrary.

Here is how you can divide the engineering colleges 

The institutes have been arranged in the decreasing order of their brand value. As far as the new IITs are concerned, I believe IIT Patna, IIT Indore, and IIT Mandi can be counted in Tier - II.