Hello Kartik, 

Park college in Madras does conduct entrance exams. For Madras Institute of Technology,  you will be selected on the basis of your merit and rank as secured in the Tamil Nadu Engineering Admissions counseling. Hindustan college too conducts an entrance exam. 

Universities in South definitely have entrance exams. It varies from college to college. Each college has their way of choosing candidates. Admission process in a particular locale cannot be generalized. 

Hope this helps :)