South Asia or Southern Asia was a subcontinent of the continent of Asia on the planet Earth, which included India and Pakistan. (TV: Day of the Daleks, Demons of the Punjab, Rosa)
In the late 20th century, amidst growing tensions between Russia and China, fighting broke out in southern Asia and South America before Sir Reginald Styles was able to negotiate peace, cooling the crisis and preventing World War III, with the Third Doctor preventing an alternate timeline where Styles was assassinated and war did indeed come to pass. (TV: Day of the Daleks)
Through biodata analysis, Bliss' ancestry was traced to there. (AUDIO: The Conscript)
Yasmin Khan, whose ancestors came from Pakistan, identified as South Asian. (TV: Demons of the Punjab, Rosa)