列国議会同盟
As Deputy Chairman Rajya Sabha, Jacob attended the Commonwealth Parliament conference in London in 1986. He was also leader of the Indian Parliamentary Delegation to Zaire in 1986 (now the Democratic Republic of the Congo), Leader of the Indian delegation to Inter-Parliamentary Union Conference in Budapest (1989) and a delegate at the Disarmament conference organised by Inter-Parliamentary Union and United Nations in Mexico (1985).