Chapter 4 of The Telecommunications Act

The Central Government may notify standards and conformity assessment measures in respect of—.
(a) telecommunication equipment, telecommunication identifiers and telecommunication network;.
(b) telecommunication services, in consonance with any regulations notified by the Telecom Regulatory Authority of India from time to time;.
(c) manufacture, import, distribution and sale of telecommunication equipment;.
(d) telecommunication security, including identification, analysis and prevention of intrusion in telecommunication services and telecommunication networks;.
(e) cyber security for telecommunication services and telecommunication networks; and.
(f) encryption and data processing in telecommunication.

(1) On the occurrence of any public emergency, including disaster management, or in the interest of public safety, the Central Government or a State Government or any officer specially authorised in this behalf by the Central Government or a State Government, if satisfied that it is necessary or expedient so to do, by notification—
(a) take temporary possession of any telecommunication service or telecommunication network from an authorised entity; or
(b) provide for appropriate mechanism to ensure that messages of a user or group of users authorised for response and recovery during public emergency are routed on priority.
(2) On the occurrence of any public emergency or in the interest of public safety, the Central Government or a State Government or any officer specially authorised in this behalf by the Central Government or a State Government, may, if satisfied that it is necessary or expedient so to do, in the interest of the sovereignty and integrity of India, defence and security of the State, friendly relations with foreign States, public order, or for preventing incitement to the commission of any offence, subject to such procedure and safeguards as may be prescribed, and for reasons to be recorded in writing, by order—
(a) direct that any message or class of messages, to or from any person or class of persons, to or from any telecommunication equipment or class of telecommunication equipment, or relating to any particular subject, brought for transmission by, or transmitted or received by any telecommunication service or telecommunication network, shall not be transmitted, or shall be intercepted or detained, or shall be disclosed in intelligible format to the officer mentioned in such order; or
(b) direct that any telecommunication service or class of telecommunication services to or from any person or class of persons, to or from any telecommunication equipment or class of telecommunication equipment, or relating to any particular subject, transmitted or received by any telecommunication service or telecommunication network, shall be suspended.
(3) The press messages, intended to be published in India, of correspondents accredited to the Central Government or a State Government shall not be intercepted or detained, unless their transmission has been prohibited under clause (a) of sub-section (2).
(4) The action specified under sub-section (1), sub-section (2) and sub-section (3) shall be for such duration and in such manner as may be prescribed.

The Central Government may, if satisfied that it is necessary or expedient so to do, in the interest of national security, friendly relations with foreign States, or in the event of war, by notification take such measures as are necessary in the circumstances of the case, including issuing directions in respect of the following, namely:—.
(a) use of telecommunication equipment, telecommunication services, telecommunication network and telecommunication identifiers;.
(b) standards applicable to manufacture, import and distribution of telecommunication equipment;.
(c) standards to be adopted by authorised entities or assignees;.
(d) procurement of telecommunication equipment and telecommunication services only from trusted sources;.
(e) suspension, removal or prohibition of the use of specified telecommunication equipment and telecommunication services from countries or person as may be notified; or.
(f) taking over the control and management of, or suspending the operation of, or entrusting any authority of the Central Government to manage any or all of any telecommunication services, or any telecommunication network or part thereof, connected with such telecommunication services.

(1) The Central Government may by rules provide for the measures to protect and ensure cyber security of telecommunication networks and telecommunication services..
(2) The measures may include collection, analysis and dissemination of traffic data that is generated, transmitted, received or stored in telecommunication networks..
Explanation.—For the purposes of this sub-section, the expression “traffic data” means any data generated, transmitted, received or stored in telecommunication networks including data relating to the type, routing, duration or time of a telecommunication..
(3) The Central Government may, by notification in the Official Gazette, declare any telecommunication network, or part thereof, as Critical Telecommunication Infrastructure, disruption of which shall have debilitating impact on national security, economy, public health or safety..
(4) The Central Government may by rules provide for the standards, security practices, upgradation requirements and procedures to be implemented for such Critical Telecommunication Infrastructure.

If it appears necessary or expedient so to do in the public interest, the Central Government may direct any authorised entity to transmit in its telecommunication services or telecommunication network, specific messages, in such manner as may be specified.