Rangin has been teaching at National Law University Odisha since 2010 and works in the area of constitutional governance, civil liberties, criminal law and human rights. His current research focuses on the functioning of institutions within constitutional democracies and the way they affect realization of democratic rights.
He was a Fulbright Post-Doctoral Research Scholar at Harvard Law School (2019-2020) where he researched on the competing methods of appointing judges in democracies. His doctoral thesis is the first work of its kind in India on performance evaluation of judges in the higher judiciary. He has completed two research projects funded by the Department of Justice, Government of India in the area of judicial reforms. He has also provided consultancy services to Odisha Judicial Academy for preparation of research materials for judicial officers.