This paper explores the making of the Mumbai Metro not as a singular system, but as an assemblage shaped by layered institutions, shifting priorities, and negotiated decisions over time. Rather than emerging from a unified vision, the network has been built corridor by corridor, each governed by distinct Special Purpose Vehicles formed in response to evolving financial, political, and implementation constraints. Drawing on theories of institutional fragmentation, institutional collective action, and path dependency, the study frames fragmentation as the dispersion of authority across multiple actors within a shared infrastructural landscape. Through qualitative analysis of policy documents, concession agreements, and project reports, it traces how successive governance models have accumulated to produce a fragmented yet functional system. The paper argues that while this structure has enabled incremental expansion, it has also embedded challenges of coordination, accountability, and integration, raising critical questions about how metropolitan transit systems are imagined, governed, and ultimately held together.