India, that teeming nation of 900 million, stands a chance of eclipsing China as a magnet for Western automakers and suppliers if judged by an overflow crowd of several hundred at a Society of Automotive Engineers conference on India's automotive industry. Although still small, some 1.2 million cars and trucks were sold there in 1995, up from 300,000 in 1987. Forecast for 2000: At least 1.5 million. Some in India predict there'll be 30 automakers and 50 vehicle varieties there by 2000. The U.S. Big Three and automakers worldwide are developing several small domestic "people's cars" in the $4,000 to $6,000 range. India's numbers look good: The gross domestic product is rising 5% to 6% yearly, industrial output is up 10% to 12%, exports are up 24%, and inflation is holding at a manageable 10%.