Hiii

You need to apply online on the official website of Jamia Millia Islamia New delhi for admission to Btech courses.
Then you need to provide your JEE Mains Marks and Ranks. After the application period ends, the selected candidte lists are released on the official site. The selection is done on the basis of your marks and ranks scored in JEE Mains exam.
The application process will be available till the month of march and has not yet started. You cn keep on visiting the official website for latest updates.
Here is the link - https://www.jmi.ac.in/
Also you can know about JMI B.Tech admissions through the following link - https://engineering.careers360.com/articles/jamia-millia-islamia-jmi-btech-admissions

Hope this helps
Thanks!