How can India qualify for World Test Championship final after win in Delhi?

India defeated Australia in Delhi and took a 2-0 lead in the four-match series. India need one more win to qualify for World Test Championship (WTC) final. India would climb to top of WTC points table if they win 3-0 or 4-0. Sri Lanka would qualify for final if they beat New Zealand 2-0 and Australia lose to India 0-4.