Hey there,

The best colleges for biomedical engineering and biotechnology in Chennai are:

Biomedical Engineering

• Alpha College of Engineering, [ACE] Chennai
• GKM College of Engineering and Technology, [GKMCET] Chennai
• Jerusalem College of Engineering, [JCE] Chennai

Biotechnology Engineering

• AIT Karaikudi - Alagappa College of Technology School of Engineering
• VELSI Institute of Science, Technology and Advanced Studies H
• Hindustan Institute of Technology and Science - HITS harath University 
• Bharat Institute of Higher  and Research (BIHER)

Hope that helps 

All the best