In 2011, France shared the list of Indians who allegedly hold bank accounts at HSBC with the government. That is "just the tip of the iceberg", Mr Falciani told NDTV.
He said India was given only 2 MB of the 200 GB of data. "If India asks tomorrow we will send a proposal tomorrow," he added.
Mr Falciani was a systems engineer at the Geneva-based private banking unit of HSBC. The bank would find later that he had carried out one of the biggest security breaches in Swiss banking history, obtaining details of some 127,000 accounts worth 180 billion euros.
He shared the data, which was a jumble of encrypted information, with France in 2008 and helped prepared the "HSBC list."
The whistleblower, who works with a team of lawyers and experts, told NDTV that there is "1000 times more information" available for investigators and there are a lot of business procedures to be unveiled to them. "It's just up to (the Indian administration). They can contact us," he said.
This week, Prime Minister Narendra Modi made a strong pitch at the G20 summit in Brisbane for "close coordination" among nations and transparency in efforts to retrieve black money.
Experts say the proof in the HSBC data leaked by Mr Falciani is damning but Switzerland has always said their laws don't acknowledge leaked data that is considered "stolen".