The nearest railway station is at Thivim, and taxi from there takes about 20 minutes and costs around Rs.300. Other railway stations are at Margao and Vasco da Gama.
Frequent state buses go to and from other parts of Goa, but if you're traveling a longer distance, you need to change buses (for example, from the airport you should need three buses to get to Calangute). A bus from Panaji costs Rs.10-15 depending on the route the bus takes.
Prepaid taxi from the outside counter on the airport costs Rs.900, while discussing the price directly with the driver should result into cheaper price.......wikitravel