Mumbai/Bengaluru, Oct. 14 -- There was no high-decibel government event, or even an investor roadshow. The message was tucked inside K. Krithivasan's prepared remarks, in a recent media release.

India's largest IT services exporter, Tata Consultancy Services (TCS), the company Krithivasan now heads, is preparing for the biggest gamble of its five-decade existence: a massive $6.5 billion investment over six years to forge one gigawatt (GW) of new data centre capacity.

Consider the sheer scale of ambition for a moment: This planned capacity alone is enough to match India's entire current data centre base within six years, and the capital expenditure eclipses the combined value of all TCS acquisitions over the last two decades.

That ambit...