Delhi university engg.colleges r admitting students on the basis of jee score. whether we have to register with these colleges in advance before the jee merit list or not?

Hello student you can register yourself before the Jee main merit list as the registration of college begin before the release of jee main result and in case if you've not registered for that particular college then you'll not get admission in that college so you should apply before the last date.
I request you to please help me with your preferable college so that I can check and provide you more exam information.

If you're preparing for jee main you should go for Jee main Knockout package its very helpful and specially designed for students to prepare and clear Jee main in single attempt.

For more updates refer to the link mentioned below
https://learn.careers360.com/knockout-jee-main-april/

Feel free to comment if you have any doubt
Good luck