The correct answer is (c) Sri Nagendra Singh.
Sri Nagendra Singh was the first Indian judge of the International Court of Justice. He was elected to the Court in 1967 and served until 1973. He was a distinguished jurist and diplomat, and served as India’s ambassador to the United Nations from 1962 to 1967.
Dr. Shashi Tharoor is a former UN Under-Secretary-General and Indian politician. He is not a judge of the International Court of Justice.
Sir B.N. Rau was an Indian jurist and diplomat. He served as India’s ambassador to the United States from 1947 to 1952, and as India’s first permanent representative to the United Nations from 1952 to 1956. He was a member of the International Court of Justice from 1958 to 1961.
Dr. B.R. Ambedkar was an Indian jurist, economist, politician, and social reformer who played a leading role in the drafting of the Constitution of India. He was the first Minister of Law and Justice of India. He was not a judge of the International Court of Justice.