What is the approximate area of a 3 BHK in Chennai?

It really defers from one project to other. Recently I went to The Ace which is located in perungudi. There they 3 bhk in two sizes one is 1000 sq.ft other one is 1687 sqft. Trust me floor plans are too good. It's in main location with good development. 

As far as India is considered , we have 2 options in 3bhk. One is the Spacious LUxury 3bhk and the other one is a Smart condo.The Size ranges from 1000-1800 on an average approximately. For Best Floorplans and construction techniques i would suggest you to look at Risland, the best in the business..