As Delhi prepares to seal, and potentially demolish, buildings that are zoned as residential and being used illegally for commercial purposes, I have to say the city's leaders are going to a lot of trouble and expense without considering the impact of their actions. Can anybody deny that if Delhi went out and sealed all the businesses operating in space not authorized for commercial use, the city's GDP would drop 20 or 30 percent? They'd be better off sealing the properties that DO have licenses.
So what should be done? Look the other way (again)? Legalize the illegal properties? Yes and no. What is needed is a full analysis of the properties in question to determine which ones have become de facto commercial areas (e.g. South Ex - who would buy a residence on the main road between South Ex part I and part II? Street noise and traffic would soon drive you insane) and identify areas that are still primarily residential but have "nuisance" commercial activity going on. Once that is done, you need a list of properties that divides the illegal buildings into three (or more) categories, including (1) suited for commercial use (2) in need of renovation for commercial use and (3) unsuited for commercial use. Those buildings that are suited for commercial use can then be converted in exchange for a hefty fee to the relevant authority. Those that need renovation would be shuttered until renovations are complete and they pay the same hefty fee, and those that are unsuited for commercial use would be closed down and converted to residences.
Maybe this is oversimplifying, but it strikes me as common sense, and far more sensible than sealing and knocking down buildings before making a plan as to what will happen to the space in the future.