Contemporary urbanism, as a science and ideology, sometimes induces a violence of urbanization that is exercised through formal planning on informal settlements. The latter are marginalized through processes of (in)visibility that exclude them from the city development. In the face of this domination, informal settlements are resisting their programmed erasure through self-construction and assemblage practices. They continue to grow massively in cities around the world, to the point of becoming the most important form of urban housing of the 21st century. By analyzing Indian informal settlements, the slums, the thesis focuses on the production of urban space and its spatial contradictions resulting mainly from a dichotomous relationship between the formal and the informal, which most often stems from the city's decision-makers. In this way, it helps to understand how norms are constantly being reworked and creating their own transgressions. This phenomenon leads to the production of a heterogeneous and multiple city. While scientific literature on slums has long focused on describing a condition considered unacceptable by elites and governments, the research is based on a field of study that attempts to highlight the reality and practices of these marginalized neighborhoods. The slum is thus established as a heuristic object in order to operate an epistemological rupture between the slum as a deficient element of the city and the slum as a driving principle of urban planning. The aim is therefore to show how slum-dwellers are resisting and overcoming, both socially and spatially, the informal status assigned to them by the Indian government, reflecting a new type of hybrid urbanity. By combining a critical approach of power relationships between dominant and dominated with empirical research carried out in several slums in Chennai (Tamil Nadu), the thesis questions the production of space in slums in two ways: the complex reality of power relations between urban planning and urban dwellers that contribute to the formation and destruction of slums; and the spatial and social practices carried out by slum-dwellers. These two ways allows us to understand the slum, not as a failure of urban development, but as a singularity of the Indian city. This recognition leads to a new urban order that considers the spatial logic of its occupants as an "alternative modernity". It makes it possible to (re)theorize the Indian city as a result of urban struggles between dominant and dominated groups as well as hybridization processes between vernacular traditions and modern practices. Considered as a theoretical figure, the slum leads to an innovative interpretation of the urban problems that constitutes an alternative to universalizing urban theories but also, and especially, to the practices that result from them. It is thus possible to consider a dialogue between modern spatial production, local practices and self-construction in order to better understand the processes of space production in Global South cities. In this manner, the slum becomes a new Indian urban paradigm, but also an universal object of contemporary urbanization that planners and architects must take into account in order to propose a type of urban planning that aims at reducing the inadequacies between "conceived space" and "lived space".