There are very few census records available to help you trace your ancestors that lived in India. Censuses were taken, mostly on a regional basis with the earliest comprehensive census taken in 1870/71, but no "as enumerated" data survives. Statistical reports of censuses are available and have been digitised by a consortium of Australian Universities.
The only known exceptions are as follows:
- 1851 Bombay Presidency Mofussil Districts - European Residents only. The data from this census is accessible through FIBIS Search. This information was originally from Valmay S. Young's British India Family History website (Census Information) and further details are available there.
- 1840 Serampore (just north of Calcutta) - this was then Danish Territory and a complete census was taken of the population, including natives. The records have been microfilmed by the LDS (Mormons), with this Library Catalogue entry. A researcher in Sydney has a list of extracted names of the European & Indo-European/community at the time - most were connected with the Baptist Mission; but there were also about 180 persons described as Indo-Portuguese; on a religion basis there were 171 Protestants, 209 Roman Catholics and 1 Armenian.
- 1834 Tranquebar - Madras Presidency - again this was Danish Territory at the time and the Danish 'as enumerated' data has been preserved and has been filmed by the LDS, with this Library Catalogue entry
- A list of individuals that are recorded on the 1881 UK census as born in India/East Indies can be found on FIBIS Search. There are over 22,000 names, transcribed by Valmay S. Young. Please note this is not an Indian census. All the individuals were in the UK in 1881.
- A list of individuals recorded in the 1841-1871 UK census as born in India/East Indies can be found at People born in India and Burma as recorded in the UK Census's 1841-1871 As above, these are individuals resident in the UK at the time of the UK census. The list does not include residents of Scotland for 1841. (archive.org link) Jon Johnson's spuddybike.org.uk
- 1911 England and Wales Census - British Army personnel in India, together with their families, appeared for the first time in an England and Wales Census in 1911. The census was taken on the night of Sunday 2 April, 1911. Search the 1911 census data. Note however, there are is at least one known instance of a soldier and his family known to be in the British Army in India at the time of the census, whose names do not appeat in the census, suggesting the data may not be complete.