When were they independent??...Apart from Kashmir, Junagadh and Hyderabad, who else revolted to stay away??
answer to that when would be 'during british rule'. the princely states accepted the suzerainty of the brits but were independent, at a price of providing money and soldiers to the brits when called for. they had their own laws, administration, armed forces and in some cases even currency.
they were as independent as, say, japan or australia or canada are wrt US.
not sure what the 'revolts', which are post independence events that have to do with this fact.