ohh Bro!!
dont laugh!! Hindi is just a official language only not a national language.
The Constitution of India designates the official language of the Government of India as Hindi written in the Devanagari script, as well as English. There is no national language as declared by the Constitution of India.
Hindi and English are used for official purposes such as parliamentary proceedings, judiciary, communications between the Central Government and a State Government.States within India have the liberty and powers to specify their own official language(s) through legislation and therefore there are 22 officially recognized languages in India.