Who was the President of India when National Emergency was declared in June 1975 ?

Fakhruddin Ali Ahmed

The correct answer is Option (3) - Fakhruddin Ali Ahmed

On the night of 25 June 1975, the Prime Minister recommended the imposition of Emergency to President Fakhruddin Ali Ahmed. He issued the proclamation immediately.
A state of emergency was declared on 25 June 1975 under Article 352 of the Constitution of India.
On 25 June 1975, the government declared that there was a threat of internal disturbances and therefore, it invoked Article 352 of the Constitution. Under the provision of this article, the government could declare a state of emergency on grounds of external threat or a threat of internal disturbances. The government decided that a grave crisis had arisen which made the proclamation of a state of emergency necessary.