There are two ways of tax permit table in India. Trading and earning is the common thing we follow in India. Here service tax is the only exempted for advertising income tax. If you earning revenue through affiliate commissions or by providing through other related services on the Internet, Service tax would be levied on all such services.
1. If you are getting this money in INR from Google, then you have to pay the service tax
2. If you get this amount in USD/ any other Forex, then there is a way to avoid service tax
Here the second option helps you to avoid tax in Adsense. If you are in service tax bracket, then you have to pay this on your revenues.