The word sovereign means supreme or independent. India is internally and externally sovereign - externally free from the control of any foreign power and internally, it has a free government which is directly elected by the people and makes laws that govern the people.
Sovereignty in government is that public authority which directs or orders what is to be done by each member associated in relation to the end of the association. It is the supreme power by which any citizen is governed and is the person or body of persons in the state to whom there is politically no superior.
It is basically a combination of all power; it is the power to do everything in a state without accountability, i.e. to make laws, to execute and to apply them: to impose and collect taxes, and, levy, contributions; to make war or peace; to form treaties of alliance or of commerce with foreign nations, and other such things.