The first complete census taken in India was in 1881.

Reasons for conducting the census:
1. The British administration wanted to gather information about the population of India for better administration and governance.
2. The census also aimed at understanding the social and economic conditions of the people.

Process of conducting the census:
1. The census was conducted by the British administration with the help of trained officials.
2. The officials went door to door to collect information about the population.
3. The information collected included age, gender, religion, occupation, literacy, etc.

Significance of the census:
1. The census provided valuable information about the population of India that helped in better administration and governance.
2. The information collected helped in understanding the social and economic conditions of the people.
3. The census helped in identifying areas that needed development and improvement.

Subsequent censuses:
1. After the first census in 1881, subsequent censuses were conducted in 1891, 1901, 1911, and so on.
2. The latest census was conducted in 2011.

Conclusion:
The first complete census taken in India was in 1881, and it provided valuable information about the population of India that helped in better administration and governance. Subsequent censuses have been conducted, and they continue to provide important information about the population of India.