In which year were the Indian states reorganised on the linguistic basis?

After creation of Andhra Pradesh as first linguistic state, there were several other demands for reorganisation of states on linguistic basis. As a result of this, a commission was setup under Justice Fazal Ali with H.N.Kunzru and K.M.Panikkar as members to study the demand. On the basis of this, State Reorganisation Act was passed in 1956. As a result, fourfold distribution of states was replaced by 14 States and six Union Territories via Seventh Constitutional Amendmert.