Part Time B.Tech

It is not possible for you to do B.Tech in part-time mode because this is against the norms of UGC and AICTE.

Go through this link. You might get an idea.
https://www.google.co.in/url?sa=t&source=web&rct=j&url=http://m.htcampus.com/college-search/part-time-b-e-or-b-tech-in-electrical-engineering/pune/&ved=0ahUKEwiG0-jA0djVAhUIrI8KHXIhDd4QFgieATAG&usg=AFQjCNFU2dfg8wQKVePZzOpWFB2hImIDAQ

Hello Prasanna,
These are following engineering colleges which offer part-time facility in Chennai:
Indian Institute of Technology, IIT madras
Meenakshi University, chennai
Indian Institute of Information Technology Design manufacturing
Asiel Academy, chennai
Central Institute of Plastic Engineering and Technology
Loyola Academy college
St. Joseph's College of Engineering
Meenakshi Sundarajan Engineering College .
Anna University.
Jaya Engineering College.
Vel Tech Technical University.
Gopal Ramalingam Memorial Engineering College.
E.V.P. Engineering College.

All part-time institutions is good of you want to study B.Tech from distance, you can find institute in your location or tell me your area name. Then, I suggest some name of distance learning centre for B.Tech.