MUMBAI (BLOOMBERG) - Billionaire Mukesh Ambani obliterated rivals in India's telecommunications sector by selling US$2 data plans and free voice calls. Four years later, he's deploying a very similar tactic - cutthroat pricing - to gain an edge in the country's increasingly competitive e-commerce space. As India this week hits the peak of its biggest shopping season, the festival of Diwali, the tycoon's retail websites - including JioMart - are elbowing their way into a space long dominated by Amazon.com and Walmart's local unit Flipkart Online Services. Ratcheting up competition, Mr Ambani's portals are offering blockbuster discounts of as much as 50 per cent on popular sugary confections and other holiday staples like spice mixes for India's rice delicacy, biryani. Meanwhile, his Reliance Digital website is selling some flagship Samsung smartphones at prices cheaper than rivals, with as much as 40 per cent rebates. It's a push that comes as Mr Ambani's sprawling conglomerate, Reliance Industries, is flush with cash. After raising an eye-popping US$20 billion (S$27 billion) for its technology venture, it's shifted fundraising to its retail arm, which has won over US$6 billion in i...