Kathrada, who frequently referred to Mandela as his 'elder brother', was among three political prisoners who were sentenced to life imprisonment together with the South African anti-apartheid icon after the infamous Rivonia Trial of 1964.
Prime Minister Modi addressed the second plenary of the executive session, during which he reiterated India's focus on small island developing nations of the organisation and delivering 'demand-driven, rather than donor-driven' assistance to the organisation's smaller member states.
Modi will first stop in Rwanda for a two-day visit, then visit Uganda from July 24-25 and finally go to South Africa.
The keynote address will be given by United States President Donald Trump
The bilateral talks took place as the formal heads of government meeting got underway in London on Thursday, following a formal launch by Queen Elizabeth II at Buckingham Palace.
President Xi said that the Chinese side is ready to work with the Indian side to carry forward the fresh impetus of bilateral relations.