India's M.G.R. Ramachandran, a former film star and the nation's best-known politician after Prime Minister Rajiv Gandhi, has died, the government said. He was 70. Doctors said that Ramachandran, chief minister of the southern Tamil Nadu state, died of a heart attack at his home in the southern city of Madras. Thousands of mourners gathered outside the home as news of his death spread. Ramachandran, known throughout India simply as "M.G.R.," had been leader of his party since rising to power in Tamil Nadu 10 years ago.