NTA has not released any official information regarding the Admit cards for DUET. But it has released the official Information Bulletin and it can be accessed at:
https://data.nta.ac.in/download/Exam/DUET/2020/NTA_UG.pdf
. Generally the admit cards are released atleast 2-3 weeks before the exam has been scheduled. As DUET 2020 schedule has not been released yet, the admit cards dates have not been released yet either. SO we have to wait for the official information. Until then, please keep an eye on the official website at:
https://nta.ac.in/DuetExam