The Ministry of Environment and Forests of the Government of India has issued a directive that all large corporations and public sector projects must have an environmental policy in place.

Companies will be required to:
(i) Adopt well laid down Corporate Environment Policy;
(ii) Ensure, as a part of this Policy, adherence with the environmental
clearances and forestry clearances wherever applicable, granted to the Company;
(iii) Ensure that inter-alia the Company functions in conformity with
the Policy;
(iv) Ensure that deviations, if any, from this Policy and cases of
violations of environmental and forestry clearances conditions that have
been found by this Ministry or other public authorities should be
duly reported to its Board of Directors and desirably reflected thereafter
on its website and its Annual Report;
(v) Identify and designate responsible person(s) at all levels of their
hierarchy for ensuring adherence to this Policy and compliance with
Environmental Laws and Regulations.

The policy will apply to companies and projects in the following sectors:
(i) All Central Public Service Undertakings
(ii) All Major Projects
• Coal Based Thermal Power Plants with capa city of 500 MW and above
• Integrated Steel Plants with capacity of 1 MTPA and above and
• Cement Plant with capacity of 3 MTPA and above
• Petroleum Refining Industries
and may be applied to projects in other sectors on a case by case basis.

The policy appears to apply equally to foreign companies operating in India as to domestic companies.

Wikipedia provides what it claims to be a current List of public sector undertakings in India at http://en.wikipedia.org/wiki/List_of_Public_Sector_Undertakings_in_India

The policy directive itself may be found at http://moef.nic.in/downloads/public-information/corporate-env-res.pdf