Hiren Bhattacharya's writings often focused on themes of social inequality, oppression, and the struggles of marginalized communities. He passionately addressed issues such as land rights, ethnic conflicts, and the exploitation of workers in his works. Bhattacharya's writing style was marked by his strong political convictions and his commitment to social justice. Some of his notable works include "Suror Putek" (The Roar of the Storm, 1962), "Itihasor Saki" (Witness to History, 1977), and "Bishesh Dristi" (Special Vision, 2007). He wrote poetry, fiction, essays, and plays, utilizing different genres to convey his messages. Hiren Bhattacharya was actively involved in various social and political movements. He fought against injustice and played a vital role in raising awareness about human rights issues. He was an advocate for the rights of marginalized communities, including tea plantation workers and indigenous peoples of Assam.