Arms and ammunition and allied items of defence equipment, defence aircraft and warships,
1. Atomic energy
2. Coal and lignite
3. Mineral oils
4. Minerals specified in the Schedule to the Atomic Energy (Control of Production and Use) Order, 1953
5. Railway transport

A departmental undertaking is established either as a separate full-fledged ministry or as a major sub-division of a ministry (i.e. department) of the Government.

(i) Departmental undertakings
(ii) Statutory corporations
(iii) Government company
(iv) Board organisation

A "Government Company" is defined under Section 2(45) of the Companies Act, 2013 as "any company in which not less than 51% of the paid-up share capital is held by the Central Government, or by any State Government or Governments, or partly by the Central Government and partly by one or more State Governments, and includes a company which is a subsidiary company of such a Government company".

(i) Department form of organisation of managing state enterprises is the oldest form of organisation. In those days, no distinction was made between the routine functions of the Government and that of the public enterprises.
(ii) Under departmental form of organisation, a public enterprise is run as a separate full-fledged ministry or as a major subdivision of a department of the Government.
(iii) The Delhi Milk Scheme, All India Radio, Doordarshan are other examples of departmental undertakings.

1. Departmental organisations - Indian Railways, Food and Public distribution.
2. Public organisations - Food Corporation of India FCI, ONGC, Oil and Natural Gas Corporation.
3. Government companies - Steel Authority of India Ltd, Tamil Nadu Transport Corporation.
4. Board organisations - Tamil Nadu Electricity Board, Tamil Nadu Slum Clearance Board.

Features of Departmental Undertaking:
The salient features of a departmental undertaking are as follows:
a) Formation:
A departmental undertaking is established either as a separate full-fledged ministry or as a sub-division of a ministry (i.e. department) of the Government.
b) No Separate Entity:
A departmental undertaking does not have an independent entity distinct from the Government.
c) Governmental Financing:
The departmental undertaking is financed, through annual budget appropriations by the Parliament or the State Legislature. The revenues of the undertaking are paid into the government treasury.
d) Accounting and Audit:
The departmental undertaking is subject to the normal budgeting, accounting and audit procedures, which are applicable to all Government departments.
e) Managed by Civil Servants:
The departmental undertaking is managed by civil servants, who are subject to same service conditions as applicable to civil servants of the Government.

Features of Government Company:
a) Registration Under the Companies Act:
A Government company is formed through registration under the Companies Act, 1956, and is subject to the provisions of this Act, like any other company.
However, the Central Government may direct that any of the provisions of the Companies Act shall not apply to a Government company or shall apply with certain modifications.
b) Executive Decision of Government:
A Government company is created by an executive decision of the Government, without seeking the approval of the Parliament or the State Legislature.
c) Separate Legal Entity:
A Government company is a legal entity separate from the Government, It can acquire property; can make contracts and can file suits, in its own name.
d) Whole or Majority Capital Provided by Government:
The whole or majority (at least 51%) of the capital of a Government company is provided by the Government; but the revenues of the company are not deposited into the treasury.
e) Majority of Government Directors:
Being in possession of a majority of share capital, the Government has authority to appoint majority of directors, on the Board of Directors of a government company.