Dtu offers btech lateral entry for which it conducts its own entrance exam called leet(lateral entry entrance exam) which you can give if you hadn't given jee mains. But btech lateral entry is different from btech. So you should apply after studying carefully about the course.
You can go through this link for further information:
http://www.admission.aglasem.com/dtu-b-tech-le/

I think DTU didn't take their own exam

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