19M and 19S will get you to the Indira Nagar water tank from where the Institute is about 5 minutes by walk. Getting transport in Madras Normal taxis are few and far between in Madras. Your best bet is the three-wheeled autorickshaw. One autorickshaw can accommodate upto three passengers. If you are staying in a a hotel, you can ask the hotel to fix up an autorickshaw for you.
Autorickshaw drivers are notorious for haggling.
These buses are rare too.