Tamil Nadu is the most populous southern state of India and has a diverse population of many religions & communities. At the census 2011, out of 7.21 Crore population, around 6.31 crores (87.58%) have returned themselves as followers of Hindu religion, 44 lakhs (6.12%) as Christians, 42 Lakhs (5.86%) as Muslims or the followers of Islam, and 0.17% as followers of other religions. In addition, 0.26% Stated no religion.
Source: Census 2011
also read Population of Tamil Nadu