Sumantra was a National Media Fellow. He did substantial research on the lives of Adivasi women living in the tea tribe community of Assam which was funded by Oxfam India. He had been awarded National Media Award by National Foundation for India 2018. Having started his career as a Communication Professional, he gained extensive experience working in diverse organizations viz. NGOs, people's movement groups and political think-tank. He also writes for Youth Ki Awaaz across subjects ranging from society and politics to human rights and Adivasis. Sumantra is passionate about cinema as an art and also produced the community short film 'Musammat'. At Josh Talks, he produced Case Study Films for brands like Meta, Ministry of Tribal Affairs, Omidyar Network, Diageo, etc.