Data on literacy rates in Tamil Nadu is collected through the:

Census
National Sample Survey (NSS)
ASER Survey
District Information System for Education (DISE)

The correct answer is: Census.

The Census is a decennial survey conducted by the Government of India to collect data on the population of India. The Census also collects data on a variety of other topics, including literacy rates. The Census is the most comprehensive source of data on literacy rates in India.

The National Sample Survey (NSS) is a large-scale household survey conducted by the Government of India. The NSS collects data on a variety of topics, including literacy rates. The NSS is a valuable source of data on literacy rates, but it is not as comprehensive as the Census.

The ASER Survey is a household survey conducted by Pratham, an NGO working in the field of education. The ASER Survey collects data on a variety of topics, including literacy rates. The ASER Survey is a valuable source of data on literacy rates, but it is not as comprehensive as the Census or the NSS.

The District Information System for Education (DISE) is a database of education data maintained by the Government of India. The DISE collects data on a variety of topics, including literacy rates. The DISE is a valuable source of data on literacy rates, but it is not as comprehensive as the Census or the NSS.

In conclusion, the correct answer is: Census. The Census is the most comprehensive source of data on literacy rates in India.