Mumbai 3 is a 64 MW AI-ready data centre at the Colt DCS and RMZ Navi Mumbai campus. It is described as delivering 64 MW of secured contracted power — the megawatts are already sold — and it is fully pre-let. Ground preparation began in December 2025; construction started on 15 October 2026, after the first hyperscale customer was signed. It takes the campus from 22 MW to 86 MW operational, against a stated potential of 148 MW, and it is cooled by a hybrid of air and direct liquid-to-chip in a closed loop with near-zero wastewater. No completion date and no building cost are published.
1At a glance
2Sixty-four megawatts of contracted power
The phrase secured contracted power is doing more work than it looks like it is.
| Statement | Holds | Implied | Strength of evidence |
|---|---|---|---|
| 64 MW of secured contracted power | Yes | Power arranged and sold | Company statement |
| Fully pre-let | Yes | Whole building committed to one customer | Company statement |
| First hyperscale customer signed | Yes | Named to the companies, not to the market | Company statement |
| Tenant identity | not disclosed | An unnamed hyperscaler | Missing |
| Lease term and rent | not disclosed | The numbers that price the asset | Missing |
| Completion date | not disclosed | Revenue start cannot be modelled | Missing |
| Building cost | not disclosed | US$1.7bn is the programme, not this building | Missing |
Three of the seven rows are missing, and they are the three that would let anyone value the asset. What the disclosure does establish is that a 64 MW AI-ready building in Navi Mumbai was sold before it was built, and that is a genuine change in the structure of the Indian market.
In September 2023 the first phase launched with 18 of 22 MW available — 82% vacant, priced by the market.
In October 2026 a 64 MW building starts construction with zero megawatts available — priced by a lease.
That is a three-year transition from speculative to pre-let, on the same fifteen acres, by the same operator. It is the most consequential shift in Indian data centre economics in this cycle.
3What 64 MW does to the campus
| Stage | MW | Share of potential |
|---|---|---|
| Mumbai 1 and Mumbai 2, live | 22 | 15% |
| Mumbai 3 under construction | 64 | 43% |
| Campus operational after Mumbai 3 | 86 | 58% |
| Remaining potential | 62 | 42% |
| Full development | 148 | 100% |
| Mumbai 3 as a multiple of live capacity | 2.9× | One building, three campuses |
One building multiplies the campus 3.9 times — from 22 MW to 86 MW. That is the same pattern as AirTrunk in Mumbai and Iron Mountain at MUM-3: in the Indian market, a single AI-specification building is worth more than the entire history of the site it sits on.
It is also why the 148 MW potential should be read sceptically. Two thirds of it is a plot, a substation and a design assumption. Only the 64 MW has a contractor on site.
The Mahape to Airoli belt now publishes, in this registry alone, AirTrunk BOM1 at 62 MW, AirTrunk BOM2 at 120 MW, L&T at 100 MW planned and this campus at 148 MW — 430 MW of published capacity within a few kilometres, against a live figure in the tens of megawatts.
4Cooling, water and the AI specification
The technical content of this announcement is more specific than most, and two details are worth isolating.
| Element | Detail | Why it matters commercially |
|---|---|---|
| Cooling architecture | Hybrid air plus direct liquid-to-chip | The only way to serve racks above about 30 kW |
| Water | Closed loop, near-zero wastewater | The binding constraint on new Mumbai capacity |
| Renewable energy | 100% | Increasingly a procurement gate for global tenants |
| Substation | 220 kV GIS on campus | The voltage class 64 MW requires |
| Power basis | Secured contracted power | Not a land capability claim |
| Density per rack | not disclosed | Cannot compute the hall count |
Direct liquid-to-chip is the tell that this building is not a 2020 colocation hall. Air cooling becomes impractical above roughly 20 to 25 kW per rack; AI GPU racks run well beyond that. Every new build in this registry that names its cooling names liquid, and it is the single best indicator that a facility is AI-era rather than retrofit.
The closed-loop, near-zero wastewater design is the other. Water is the constraint nobody prices yet: Mumbai and Chennai data centres draw heavily on municipal supply, and the operators that publish water-neutral cooling designs will win the next round of hyperscale tenders on that alone.
Neither of those facts is in a capacity total. Both change what a megawatt in this building is worth.
5Procurement
6Limits and open questions
- No completion date. Neither party discloses when the building delivers.
- No building cost. US$1.7 billion is the JV programme across Mumbai and Chennai.
- The tenant is unnamed and no lease term is published. Concentration and duration risk cannot be assessed.
- 64 MW is secured contracted power, and the IT versus gross basis is not stated.
- Rack density is not disclosed, so the number of data halls and the IT fit-out cannot be computed.
- 700+ jobs is a company claim and is not verified.
- 64 MW is counted. It is the only megawatt figure in this campus family that enters a national total.
- What would close it. A completion date and a named tenant. Both are knowable and neither is public.
7Sources
Sources: the Colt DCS and RMZ Mumbai 3 release of 15 October 2026; PR Newswire and Yahoo Finance distribution of the same release; ET Datacenters, Datacenter Magazine, Data Center Dynamics, The Tech Capital and CRN Asia coverage; and Unite.AI.