The e-commerce major also announced that it will look at three-four acquisitions in the coming few months in mobile technology and intended to set up an incubation centre in six months to harness start-up businesses in this fast-growing space.
Once the funding deal reaches closure, Snapdeal would have raised some $1 billion this year, including $133.77 million in February from eBay and $105 million in May from such investors as Temasek, Myriad, Tybourne, BlackRock and Premji Invest.
The details of how much stake the investment will fetch was not disclosed.
"We believe India is at a turning point in its development and we have confidence that India will grow strongly over the next decade," said Masayoshi Son, chairman of SoftBank who is in India and met Prime Minister Narendra Modi Monday.
"As part of this belief, we intend to deploy significant capital in India over the next few years to support development of the market," he said, adding it was a part of his group's strategy to contribute to people's life through information technology.
In recent months, another Indian e-commerce major Flipkart had said it will raise $1 billion in funding, even as the US-based global e-retailer Amazon said it would invest $2 billion in India.
Founded just four years ago in 2010, Snapdeal has emerged among the fastest-growing online marketplace in India and now claims more than 25 million registered users and over 50,000 business sellers.
The e-retailer said it also intended to open innovation centres across the country and that after the first one in the nation capital, it had already opened another in India's tech capital Bangalore. Soon Hyderabad and Pune will follow.
The company said it will also double its technology team size to 1,000 people by the end of the current financial year and expand its supply chain efforts to 30 cities. It now has 40 fulfilment centres in 15 cities.
Kunal Bahl, co-founder and chief executive of Snapdeal, also announced that Nikesh Arora, vice chairman of SoftBank, will join his company's board and that the group will also seek to address the needs of one million small businesses in India.
During his India visit, the SoftBank chief executive Masayoshi had told Prime Minister Modi and Communications and IT Minister Ravi Shankar Prasad that his group will invest $10 billion in India, as it has been identified as a priority market.
With a market cap of $92 billion, SoftBank is one of the largest players in the telecom and Internet investment space. It already has made investments in many Indian companies like InMobi and Hike.