First of all they can't do it. Yes, to fool people, they will try it with smaller rivers here and there. That's all. Nothing more.
By this project, they are trying to convince everyone that it can be healing India's water shortage problems, but in fact, if this, by any chance, culminates, the monsoon will never be the same, the biodiversity won't be the same, the ecosystem in which India is located right now would not be the same.
In short, it's just another propoganda plan to give a false hope to people. NOBODY CAN AND NOBODY SHOULD PLAY WITH NATURE IN LARGE SCALES.