Hello,

College of Engineering, Trivandrum does not offer diploma course. It offers undergraduate and postgraduate Engineering, research programs and other short term courses. You can check the courses offered here https://www.cet.ac.in/

And yes, there are entrance exams for admission to diploma. And in few states the admission to diploma is based on merit in class 10. Please click the link below to read the article about diploma courses, eligibility requirement, list of colleges, entrance exams etc https://engineering.careers360.com/articles/polytechnic