The 1981 Census of India could not be conducted in which of the following Indian states?

The correct answer is Assam . Key Points The 1981 Census of India could not be conducted in Assam due to the ongoing political unrest and the Assam Agitation. The Assam Agitation (1979–1985) was a mass movement against illegal immigration and the demand for identification and deportation of illegal immigrants in the state. Consequently, the population of Assam in the 1981 Census was estimated based on interpolation rather than actual enumeration. The unrest in Assam led to the signing of the Assam Accord in 1985, which addressed issues related to illegal immigration and voter registration. Additional Information Census of India: Early British Efforts : Town censuses by James Prinsep (Allahabad, 1824) & Henry Walter (Dacca, 1830). 1872 : First non-synchronous census under Lord Mayo. 1881 : First synchronous (all-India) census, marking regular decennial counts, under W.C. Plowden. 1921 : The only decade with a population decline (due to the 1918 flu pandemic). 1951 : First census after independence, under the Registrar General & Census Commissioner.