Which Act provided for the establishment of an All India federation at the centre consisting of the provinces of British India and the princely states?

The Government of India Act 1935, This act ended the system of dyarchy introduced by GOI Act 1919 and provided for establishment of a Federation of India to be made up of provinces of British India and some or all of the Princely states. However, the federation never came into being as the required number of princely states did not join it.