Not like that. India is huge. Military in itself has 5 commands. Its impossible to take head of every command in coup plans. Secondly, Delhi is not India. Capturing PM alone in a coup has no value. Until unless, you capture 30 states Chief Ministers and their ministers and put them under house arrests. Arresting someone like Jaya, Mamata, Chandra Babu Naidu will bring lots of people into streets, uncontrollable mobs. How many people can Army kill?
Killing people will fail the coup itself. India is huge. Its a advantage. The only ever possibility of India being in a dictatorship was the presence of Nethaji Subash Chandra Bose. Indian people would never think twice of installing him as their king, even 10 years of Nehru rule.