Hello, Subash!

So, ideally please provide more specifics so we can help you better!

Otherwise, the top 10 'government' engineering colleges in Tamil Nadu would be-

IIT Madras - 1st, undoubtedly.

National Institute of Technology, Tiruchirapalli.

Anna University Engineering Department, Chennai.

Alagappa College of Technology, Chennai.

Coimbatore Institute of Technology, Coimbatore.

Madras Insititute of Technology, Chennai.

Government College of Technology, Coimbatore.

DR MGR Educational and Research Institute, Chennai.

Annamalai University, Annamalai Nagar.

Government College of Engineering, Salem.

There are other really good colleges for engineering too. 

Hope this helped, good luck!

• Indian Institute of Technology Madras
• National Institute of Technology Tiruchirappalli
• Alagappa College of Technology, Chennai
• Anna University, Chennai
• Coimbatore Institute of Technology, Coimbatore
• Government College of Technology, Coimbatore
• Indian Institute of Information Technology Design and Manufacturing Kancheepuram
• Madras Institute of Technology, Chennai
• Dr MGR Educational and Research Institute, Chennai
• Government College of Engineering, Bargur

All the Best