what was its role during emergency?
A state of emergency enabled the central government to issue executive decrees without requiring the consent of Parliament.
Emergency
 A state of emergency enabled the central government to issue executive decrees without requiring the consent of Parliament. 
who was the first president of india to be elected unopposed Neelam Sanjiva Reddy was he involved in freedom struggle? Yes, he joined the Indian struggle for independence. which other political posts did he have? President of the Indian National Congress, Union Minister of Steel and Mines, Union Minister of Transport, Civil Aviation, Shipping and Tourism, speaker of the Lok Sabha, etc. which political party was he associated with? Indian National Congress Party in the Indian independence movement and Janata Party as a candidate for Parliament. when was the second political party established? 23 January 1977
UNANSWERABLE They opposed to the Emergency that was imposed between 1975 to 1977 by Prime Minister Indira Gandhi of the Indian National Congress. When the State of Emergency was lifted and new elections called in 1977 the Janata Party won a majority in the Indian Parliament.
Janata Party Janata Party
Introduction Introduction
opposed to the Emergency that was imposed between 1975 to 1977 by Prime Minister Indira Gandhi of the Indian National Congress. When the State of Emergency was lifted and new elections called in 1977, opposition political parties such as the Congress (O), Bharatiya Jana Sangh, Bharatiya Lok Dal as well as defectors from the Congress (R) joined to form the Janata party, which won a sweeping majority in the Indian Parliament. Narain defeated Gandhi at Rae Bareli in those elections.

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Janata Party [SEP] Emergency
On 25 June 1975, the President of India, Fakhruddin Ali Ahmed, accepted prime minister Indira Gandhi's recommendation to declare a state of national emergency. Indira argued that the political and civil disorder constituted a threat to national security. A state of emergency enabled the central government to issue executive decrees without requiring the consent of Parliament. Elections were postponed and public gatherings, rallies and strikes were banned. Curfews were imposed and police forces were empowered to make warrantless searches, seizures and arrests. Indira's government imposed "President's rule" in the states of Tamil Nadu and Gujarat, dismissing the governments controlled by opposition political parties.