Part Time B.Tech

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.

DTU is an university approved by UGC. Therefore, it does not require AICTE approval for its technical degrees. It is the primer University and you are in the hands of of the best faculty. You should have no inhibitions. You will be eligible for higher studies in India or abroad and also job in both Government and Private sector.

Hello Pradeep,
Surely, you can apply for part-time B.Tech after completing class 12th. Kindly refer to the link mentioned below for more information on the colleges:
https://goo.gl/l1X2Lm
Kindly filter the results based on your location preferences.
I hope this answers your question to your satisfaction. If so, kindly upvote this answer. If you have any further questions, kindly revert.

Dear Utkarsh Giri,
You can do part time B.Tech through distance university. There are many universities available which provides distance education are Jaipur University and Karnataka State Open University.