The Bharat Stage (BS) norms are equivalent to Euro norms on emission. The Ministry of Road Transport and Highways has issued a Notification No. GSR 555(E) dated 14.7.2015 regarding Introduction of BSIV fuel in additional cities.
Links:
[1] http://admin.indiaenvironmentportal.org.in/reports-documents/notification-regarding-introduction-bsiv-fuel-additional-cities
[2] http://admin.indiaenvironmentportal.org.in/category/publisher/ministry-road-transport-and-highways
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/bharat-stage-iv
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicles
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/urban-transport
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/fuel-standards
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/fuel-quality
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/motor-vehicle-act-1988
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/motor-vehicles-rules-1989