As a carmaker, he secured concessions in one of India’s most protected sectors; as an internet provider, he turned potential competitors—and two of India's richest men—into partners. But Elon Musk’s mettle as India's most influential overseas businessman has been put to another test now.Musk’s X Corp., previously Twitter Inc., sued the Indian government in the Karnataka High Court this month, alleging that the central government is unlawfully censoring content on the microblogging platform.