http // w w w infosys com/investors/investor-services/FAQs.asp
15) What is an American Depositary Share (ADS)?
An ADS is a negotiable certificate evidencing ownership of an outstanding class of stock in a non-US company. ADSs are created when ordinary shares are delivered to a custodian bank in the domestic market, which then instructs a depositary bank in the US to issue ADSs based on a predetermined ratio. ADSs are SEC-registered securities and may trade freely, just like any other security, either on an exchange or in the over-the-counter market.
16) What is the ratio of equity shares to ADS?
1 equity share held/traded in India is equivalent to 1 ADS held/traded on NASDAQ
Guess this clarifies, Infy`s info cant be wrong pls...!!!