<Tr> <Td> Politics (show) <Ul> <Li> Politics of Tamil Nadu </Li> <Li> Dravidian Nationalism </Li> <Li> Tamil Nationalism </Li> <Li> Sri Lankan Tamil nationalism </Li> </Ul> </Td> </Tr> <Ul> <Li> Politics of Tamil Nadu </Li> <Li> Dravidian Nationalism </Li> <Li> Tamil Nationalism </Li> <Li> Sri Lankan Tamil nationalism </Li> </Ul> <Li> Politics of Tamil Nadu </Li> <Li> Sri Lankan Tamil nationalism </Li>

When did tamil became official language in tamilnadu