Here is the list of top engineering colleges in Tamil Nadu with good placements :

1) IIT MADRAS
2) NIT , THIRUCHIRAPALLI
3)VELLORE INSTITUTE OF TECHNOLOGY
4) COLLEGE OF ENGINEERING GUINDY , ANNA UNIVERSITY
5)SRM INSTITUTE OF SCIENCE AND TECHNOLOGY
6)SSN COLLEGE OF ENGINEERING
7) PSG COLLEGE OF TECHNOLOGY
8)THIAGARAJAR COLLEGE OF ENGINEERING
9) KARUNYA INSTITUTE OF TECHNOLOGY AND SCIENCES
10)BANNARI AMMMAN INSTITUTE OF TECHNOLOGY, ERODE
11) SASTRA UNIVERSITY, THANJAVUR
12)AMRITA VISHWA VIDYAPEETHAM COIMBATORE CAMPUS , COIMBATORE

https://engineering.careers360.com/colleges/ranking/top-engineering-colleges-in-tamil-nadu

Visit this link and you will get to know the top ranked colleges in Tamil Nadu. Also, a lot of information is provided in details for a better understanding and comparison