First off never believe what most of the Indian posters say here. The education is terrible(look up the education budget for that), which results even in the basic distinction between GDP and annual union budget incomprehensible for indian posters here, as you saw in some of the replies. Idiots don't even know what GDP is.
Second, never quote wikipedia! Wikipedia is edited by amateurs with no or out of context references and is the most inaccurate source of info on the web.
Official govt website:
Union Budget 2014-2015 | National Portal of India
17948.920 billion rupees, which is about 269 billion USD.
Another book source which says 270 billion dollars.
Business Marketing: Concepts and Cases - Google Books
And 18% of 270 comes to about 47 billion dollars.
And third, the state govt budgets are extremely paltry. Even in the prosperous southern states, the healthcare is only 5% of the total state govt budgets. In some of the northern states its less than 2 percent. And India is like the corruption king of Asia, and most of the corruption is concentrated in state governments. So you can reduce the 5% and <2% to half.
This is a country which buys gold plated fighter jets, and embarks on finding the compounds for basic necessities for life on other planets but can't provide the basic necessities for life for its people in its own land.