What is the best thing in Madras institute of technology?

To be honest, there are tonnes of “best things” about MIT that any other college would rarely offer you. Here I'm giving a few glimpses:

• Senior - Junior Bonding: MIT is mostly recognized for its unique custom, i.e. ‘Senior - Junior Relationship’. The institute has a practice called "T-series" - a system of student mentoring by senior students to the juniors having the familiar registration number. This Mentor-ship activities span a whole gamut of student activities starting from passing on books, counseling, monetary help if needed, and placement preparation.
• Life Lessons: Being on campus, dealing with the day-to-day problems makes you independent. The last-minute assignments, deadlines which may seem scary at times actually prepares you for the future. 
• Diverse Peer-Group: At the campus, you will meet people from different states, different backgrounds. You will get to learn a lot from them. Some friends and memories that you make during your time will stay with you for the rest of your life. 
• Events: The events and fests conducted are great. Once you are a senior you will get to organize the events too. 

Hope this gives you an idea of what to expect. You'll come across many other "best things" once you come here.