There are a number of big players like Hero Motors, TVS Motors, Kinetic Motors who have introduced some e-scooters and are introducing more models in coming months.
Also, there are a number of small players like Yo Bikes (Yash E-bikes?), Vijaya Electrics, Atlas Cycles, Avon Cycles to name a few.
Some of the best information sites for E-bikes include EVFuture.com which includes a complete list of players in this niche space and also includes pictures of vehicles with prices for some of them(http://www.evfuture.com/products/electric_scooters).
Watch out for the following models:
Hero Ultra's VeloPlus (http://www.ultramotor.com/India/Products/ProductDetails.aspx?gProductId=73#)