It is not that simple.
In this case, it is the annual Diwali festival and transport and agricultural activities contributing to smog. Energy is part of the equation, but not everything. Those agricultural waste could be used for energy, or to create a nonexisting district heating system. Bus lanes were tried, but discarded. They should try it again.
About Nuclear, it is easier when you are part of the cool club, which India is not
https://en.m.wikipedia.org/wiki/Nuclear_Suppliers_Group