Explanation:

 Hindustan Socialist Republican Association (HSRA) was a revolutionary organisation, also known later (in 1928) as Hindustan Socialist Republican Army established in 1924 at Feroz Shah Kotla in Delhi by Sachindra Nath Sanyal, Chandrasekhar Azad, Bhagat Singh, Sukhdev Thapar and others were members of this association .[1] Previously it was known as Hindustan Republican Association (HRA) whose written constitution[2] and published manifesto titled The Revolutionary[3] were produced as evidence in the Kakori conspiracy case of 1925.