More capital investments in urban cities grew an unprecedented demand of talent, industrial and manufacturing workers. Urbanization was the answer in which rural population migrated to urban cities and settled. The urbanization drive was a wonder in itself, as there was no conceivable idea of an economic collapse and sudden loss of jobs. This was seen largely in China that was consumed about urbanization and wanted every farm worker or rural resident to come to work in urban factories immediately, which built urbanization beyond boundaries (Evans, 2001). Likewise, Mumbai became the magnet of economic prosperity for rural migrants coming from far flung states that were deprived of development and opportunities. Urban slums are defined as the cluster of housing that does not come up on private, government, or public land and occupy it without legal permission or acknowledgement. However, there are external factors that are equally responsible in the rise of slums as economic advantage. Two of these are the international institutions and their policy impacts, and the obstacles and successes of scaling up slum upgrading interventions. These two should be discussed in detail in the context of the case study of Mumbai.