India's potential in the field of travel and tourism is hardly close to being fulfilled. The country is a geographical anomaly, having almost all the geographical features available.
According to a report published by the World Travel and Tourism Council (WTTC), India could possibly add another Rs. 8,50,000 crores by the year 2020 just through tourism! WTTC calculated that tourism generated 8.31 lakh crore or 6.3% of the nation's GDP in 2015 and supported 37.315 million jobs, which is about 8.7% of its total employment.
This presentation discusses the matter in more details.