JEE Main

No, the aspirants of BTech at IIT Delhi must have a valid score of JEE Main. The admission in Indian Institute of Technology (IITs) is through NTA JEE only. Moreover, students who pass the JEE Main exam also have to appear for the JEE Advanced examination. The candidates who pass JEE Advanced become eligible for admission in IITs. These candidates are further allotted seats through JoSAA counselling. 

Noramlly, with these percentile you can easily get ECE, but I am not sure about other state cutoffs.

If you belong to the OBC or general category, it is not possible to get CSE.

Yes, admissions are possible without the JEE Main entrance exams. The other accepted entrance exam is HPCET. Candidates willing to get admission must first visit the official website. Then click on the Apply Now tab. Then, select the required course. Then, pay the application fee. Then, fill out and submit the application form with the required information.

There are more than 180 BTech Mechatronics Engineering colleges in India, out of which around 65 colleges accept students on the basis of JEE Main exam scores for admission. You need to work really hard to get an excellent score and rank in the exam to get a seat at top colleges. A few colleges that accept the JEE Main exam scores include Thapar University, LPU, SASTRA University, NIT Patna, and Manipal University (Jaipur).