When the dollar fails, and currency are devalued, barter begins:

India, the world's fourth-largest oil consumer, relies on Iran for about 12 percent of its imports or 350,000-400,000 barrels per day (bpd) and is Tehran's second-biggest oil client after China. But Washington has snapped tighter financial sanctions on Iran and wants Asia, Tehran's biggest oil market, to cut imports in a bid to pressure the Islamic nation to rein in its nuclear ambitions, which it suspects are aimed at making weapons.

India Trade Secretary Rahul Khullar said this week that the Indian delegation to Iran would work around the U.S. sanctions to protect oil supplies and promote Indian exports.

The government source said Iran has agreed to step up imports from India which added up to some $2.7 billion in 2010/11 and including oilmeal, rice and
tea.

"This will cushion them (Iran) to some extent from exchange rate volatility," the source said.
http://www.zerohedge.com/news/india-joins-asian-dollar-exclusion-zone-will-transact-iran-rupees