Most investors know the names at the top of India's data centre boom — Reliance, Adani, the hyperscalers. What they often miss is the ecosystem of midcap companies quietly building the infrastructure that makes all of it possible. The wires. The pipes. The power systems. The cooling equipment. The data centres themselves.

These are the companies that do not make the press release when a hyperscaler announces a $10 billion India investment. But they are the ones that get the orders when the ground is actually broken.

India's data centre capacity currently sits at approximately 1.5 GW. According to Bernstein, it could reach the upper end of a 5–8 GW target by 2030. Global hyperscalers — Amazon, Microsoft, Google, and Meta — have collectively committed over $650 billion to new data centre and AI infrastructure. Every dollar of that commitment creates demand across a supply chain that runs from optical fibre to power generators to real estate.

Here are six midcap companies positioned at different points along that supply chain — each expanding capacity ahead of the wave.

1. STERLITE TECHNOLOGIES — THE OPTICAL NERVE OF THE NETWORK

Sterlite Technologies is India's largest end-to-end optical fibre manufacturer with an 8% global market share outside China — and it is becoming the company of choice for hyperscaler connectivity requirements.

STL has secured a $1.1 billion multi-year order from a hyperscaler for optical connectivity products, scheduled for execution by FY29. Scaling the Enterprise and Data Centre segment is a core strategic priority for FY27 — it accounted for 19% of STL's revenue in FY26, with management planning to increase it to 30% in FY27. STL plans to spend ₹5.0 billion on capex to upgrade its asset base and maintain technology leadership. STL launched India's first hollow core fibre cable delivering 30–47% lower latency supporting bandwidths from 800G up to 1.6T — critical for hyperscale GPU clusters.

Revenues grew 19% YoY to ₹47.4 billion in FY26. EBITDA grew 39% to ₹6.3 billion with margins at 13.2%. STL turned profitable at ₹560 million from a loss of ₹1.2 billion in FY25. STL aims to achieve a 20% EBITDA margin by end of FY27.

2. WELSPUN CORPORATION — THE PIPES THAT POWER AI

This one surprises people. A pipe manufacturer as a data centre play? The connection becomes clear when you understand that AI data centres in the US run on natural gas — and that gas travels through large-diameter line pipes. Welspun makes those pipes.

Welspun holds a dominant 33–35% market share in the US large-diameter line pipe segment. Currently all pipes produced in the US are specifically allocated for LNG exports or fuelling AI data centre power plants. Welspun's record global order book stands at roughly ₹253.5 billion, with US spiral mills fully booked through FY28. Two new US pipe facilities are scheduled for commissioning in FY27.

Revenues grew 20% YoY to ₹167.7 billion in FY26. EBITDA grew 28% to ₹23.7 billion with margins at 14%. Net profit grew 42% to ₹16.1 billion. Management aims to grow revenue by 19% to reach ₹200 billion in FY27.

3. MTAR TECHNOLOGIES — FUEL CELLS FOR THE DATA CENTRE AGE

MTAR's connection to data centres runs through Bloom Energy — a leading provider of on-site solid oxide fuel cell power for data centres — for which MTAR supplies 50–60% of hot box requirements.

MTAR expanded hot box capacity from 8,000 to 12,000 units in FY26 and plans to scale to 20,000 units by December 2026 and 30,000 units subsequently. The company has entered a long-term contract with SLB to supply data centre infrastructure components — estimated to generate ₹4–5 billion in revenue over the next couple of years. Total capex planned over two years stands at ₹2.5–3.0 billion.

Revenues grew 29.6% YoY to ₹8.8 billion in FY26. EBITDA grew 41.7% to ₹1.7 billion with margins at 19.5%. Net profit surged 76% to ₹940 million. Revenue is expected to grow 80% in FY27, backed by a ₹53.3 billion order book — six times FY26 revenue.

4. ANANT RAJ — THE REAL ESTATE PLAYER THAT BECAME A DATA CENTRE DEVELOPER

Anant Raj's transformation from traditional real estate developer to data centre operator is one of the more interesting strategic pivots in Indian midcap investing.

The company has 28 MW of operational IT load capacity with an EBITDA margin of approximately 75% for colocation and cloud services. Anant Raj has laid out a clear roadmap to reach 357 MW of total IT load capacity by FY32 across Manesar, Panchkula, Rai (Sonipat), and Andhra Pradesh. It targets 63 MW by December 2026, expected to generate ₹12 billion in revenue at full occupancy by FY28.

Revenue grew 22% YoY to ₹25.1 billion in FY26. EBITDA grew 36% to ₹7.2 billion with margins expanding 271 bps to 28%. Net profit surged 31% to ₹5.6 billion.

5. TD POWER SYSTEMS — BUILDING THE GENERATORS THAT KEEP THE LIGHTS ON

TD Power Systems makes generators and motors for gas turbines and gas engines — and AI data centres need a lot of both.

Management notes that power needs for the AI data centre market in the US alone are projected at around 100 GW over the next 5–7 years. TDPS is entering the 200 MW generator business from its current 40–50 MW range. The unexecuted order book stands at ₹19.7 billion as of March 2026. TDPS plans to invest ₹1 billion by FY28 to automate and expand revenue-generating capacity to ₹30–32 billion.

Revenue grew 45% YoY to ₹18.7 billion in FY26. EBITDA grew 41% to ₹3.4 billion. Net profit surged 36% to ₹2.4 billion. Management has guided for ₹24 billion of revenue in FY27.

6. HFCL — THE DARK FIBRE PLAY THAT MOST DATA CENTRE INVESTORS ARE MISSING

HFCL's data centre connection runs through two channels: optical fibre cables — where AI GPU racks need 36 times more fibre than traditional CPU racks — and data centre interconnect solutions linking servers at 400G and 800G speeds through its subsidiary HTL Limited.

HFCL secured a ₹10,159 crore multi-year OFC supply agreement with a global hyperscaler — the largest export order in its history — anchoring 50% of its OFC capacity through FY29. Export revenue jumped from ₹497 crore in FY25 to ₹2,047 crore in FY26, representing 41% of total revenue.

HTL data centre interconnect solutions are expected to contribute ₹400 crore in FY27, rising to ₹800 crore in FY28. Full-year FY26 revenue hit a record ₹4,949 crore — up 49% YoY. EBITDA reached ₹826 crore with net profit up 90% to ₹329 crore. Management has guided for 20–25% revenue growth in FY27 with 3–4% EBITDA margin expansion, backed by a total order book of ₹21,206 crore.

THE COMMON THREAD

What connects all six companies is not that they are data centre developers. It is that they are infrastructure enablers — providing the physical products and services that make data centres possible, at a moment when demand is growing faster than any of them can currently supply.

Whether it is optical fibre connecting GPU clusters, large-diameter pipes feeding gas turbines, fuel cells providing on-site power, power generators supplying backup capacity, real estate converted to hyperscale capacity, or interconnect cables linking servers at 800G speeds — each of these six companies sits at a point in the supply chain where demand is guaranteed, capacity is constrained, and pricing power is real.

The risk, as with any infrastructure theme running hot, is whether project timelines slip. Data centre construction projects regularly face delays from land acquisition, power connectivity, and equipment supply challenges. Companies that have expanded capacity ahead of project confirmation carry execution risk if the wave takes longer to arrive than expected.

But for investors with a 3–5 year horizon, prepared to do the fundamental work to distinguish companies with real order books from those riding a narrative, these six represent the most direct midcap exposure to India's data centre buildout available today.