Complex sentence: Cripps was sent to negotiate an agreement with the nationalist leaders Gandhi speaking for the Hindus and Muhammad Ali Jinnah for the Muslims, that would keep India loyal to the British war effort in exchange for a promise of full self-government after the war.
Split into simpler sentences: Cripps was sent to negotiate an agreement with the nationalist leaders Gandhi, speaking for the Hindus, and Muhammad Ali Jinnah, speaking for the Muslims. Cripps worked to keep India loyal to the British war effort in exchange for a promise of full self-government after the war.