Plan Balkan was

a plan devised by Mountbatten to transfer power to separate provinces or confederation of provinces, with the Bengal and Punjab Assemblies being given the options to vote for partition of their provinces

The plan devised by Pethick Lawrence to give autonomy to Indian princes and provinces

A plan devised by the Muslim League and the Congress to provide autonomy to Indian provinces to form confederations

A plan devised by Mountbatten to allow Indian princes the freedom to either be independent or to join either India or Pakistan