Some more tips which i understood as a Traveller in Chennai
1) As you seem to be a tourist, try and understand from the locals which are the different ways to reach a particular place. For e.g. if I had to take train from Chennai Airport to Koyembedu Bus station, I was suggested a Metro (Rs. 50), however a normal local train would charge only Rs. 5. It took me only Rs. 5 by the local train from Chennai Egmore Station to Tirusulam Station!, which is just 10 mins walking distance from the Airport and the Metro.
2) Chennai is a safe place to move around and eat, even the R water at Chennai Station is safe enough. Trial, tested and tasted by me :)
3) Rickshaws for site seeing charge as per the things you wish to see. Dont agree or settle for anything more after you have set a deal.
4) Site seeing Chennai, for a day is more than enough
Total cost of Chennai for me, apart from Train and flight journeys is as below
a) Chennai half day tour by Rickshaw - Rs 650
b) Lunch (Chicken Biryani) opposite Chennai Egmore Station - Rs. 70
c) Cripsy Vadas - Rs. 15
d) Water from Egmore Station - Rs. 5
e) Eateries at T Nagar - Rs. 20
f) Train from Egmore to Tirusualam -Rs. 5
Total : Rs 765 (~ Rs 800)