> Amazon's capital has gotta run out at some point in time
They're famous for being willing to push competitors into the ground on margins, at whatever loss is necessary in the relative near-term. It's very likely they're going to seek to squeeze Flipkart on margins until they're struggling to operate due to a very high cash burn (with venture capitalists eventually unwilling to keep pouring red ink down the drain).
I'd bet that Amazon views India as a truly massive future market. They really can't crack China properly, and likely never will. India however, they can crack. They'll pour vast resources into it to build out a dominant position. If you told Amazon they can own a dominant position in India for the next 30 years by spending $10 billion today, they'd write that check immediately.
They're the world's largest retailer by market valuation, and carry $14.4 billion in cash (with the ability to raise whatever sum they need at any time they need it). Further, AWS has become a cash generating monster, that will fund any adventures Amazon wants to undertake over at least the next decade.
No chance they run out of capital.