HIndi is one of the national languages of Indian no the only one. Read yor constitution first. Tamil is the oldest living language in India, its sister language Sanskrit which existed with it is long dead. The history of Tamil/old Tamil is around 5000 years old ( in undivided India). COmpared to HIndi which is only a few centuries old. so thier hold and claim to India is far stronger than the other liguistic groups. who only originated much later. (Other than the Muda tribals.) So think before yo make comments.
