India’s economy is already around $10 trillion if measured at the 2011 exchange rate, when the US dollar was around ₹44.
Indian government has allowed the rupee to depreciate over time, which is one reason India’s nominal GDP appears smaller in dollar terms, even as exports are expected to cross the $1 trillion mark this year.
nominal GDP figure can be misleading if you want to assess the overall financial and economic strength of a country. It is better to also look at foreign-exchange reserves, total exports and imports, domestic consumption, industrial production, air passenger traffic and vehicle sales.
Don’t read too much into nominal GDP alone. A depreciating currency can make a country’s economy look smaller in dollar terms even when its real economic activity is much larger. Just look at India’s air passenger traffic and passenger-car sales, the current $4.6 trillion nominal GDP figure can look like a significant understatement of the scale of the economy.