(a) in any Central Act passed after the commencement of Part III of the Government of India Act, 1935 , shall mean any part of His Majesty' s dominions exclusive of the British Islands, the Dominions of India and Pakistan (and before the establishment of those Dominions, British India), any Dominion as defined in the Statute of Westminster, 1931 , any Province or State forming part of any of the said Dominions, and British Burma; and