When it receives petitions about violation of environmental laws such as illegal construction in eco-sensitive area.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/national-green-tribunal-launch-online-complaint-system
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/deccan-chronicle-telangana
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/telangana
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/eco-sensitive-zone
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/national-green-trbunal-ngt
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environmental-security
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment