New Delhi: The government on Monday constituted a high level steering group headed by industrialist Ratan Tata to draw up an action plan to promote hydrogen usage, including the commercialization of technologies for vehicles based on alternative fuels. The group also comprises Anand Mahindra, who will be the chairman, besides representatives from governmental departments and scientific bodies, the non conventional Energy Sources Minister Kariya Munda said here on Monday. The group would report back to the government within four months, suggesting plans for the demonstration and commercialization of hydrogen and fuel cell powered vehicles and power generation systems through public-private partnership.