In case a vehicle is registered as commercial but is transporting essential goods and services, the driver will be allowed to claim a refund.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/delhi-tag-system-fix-congestion-pollution-city-entry-points
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/indian-express-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicular-pollution
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/municipal-corporation
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/congestion
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/centre-science-and-environment-cse