<P> In 1961, India proclaimed that Goa should join India "either with full peace or with full use of force". In August 1961, India began military preparations and, following Nehru's announcement on 1 December 1961, that India would not remain silent in relation to the Goan situation, Indian troops were strategically stationed close to the Goan border . </P> <P> After failure of diplomacy with the Portuguese, Nehru ordered the Indian Armed Forces to take Goa by force . In a military operation conducted on 18 and 19 December 1961, Indian troops captured Goa with little resistance . The governor - general of Portuguese India signed an instrument of surrender . </P> <P> Major General Kunhiraman Palat Candeth was appointed military governor of Goa that was first created by British government in 1934 . In 1963, the Parliament of India passed the 12th Amendment Act to the Constitution of India, formally integrating the captured territories into the Indian Union . Goa, Daman and Diu became a Union Territory . Dadra and Nagar Haveli, which was previously a part of the Estado da India, but independent between 1954 and 1961, became a separate Union Territory . </P> <P> In October 1962, Panchayat elections were held in Goa, followed by assembly elections in December 1962 . On 16 January 1967, a referendum was held in which the people of Goa voted against merger with Maharashtra . Portugal recognised Goa's accession into the Indian union only in 1974 . In 1987, Goa was separated from Daman and Diu and made a full - fledged state . Daman and Diu continued as a new Union Territory . </P>

Who amended its constitution and declared goa as its state