Raj practices in the fields of civil, criminal and constitutional law. There are about five hundred reported judgments on which he is counsel of record. Before the Supreme Court of India, in Joseph Shine v Union of India, he appeared as the lead counsel for the petitioner. In that case, the top court of India struck down Section 497 of the Indian Penal Code, which criminalised adultery, as unconstitutional.
He also appeared before the Supreme Court of India in the Government advertisements case (2015), Kerala Liquor Policy case and National Highway liquor ban case (2017). He was appointed as Amicus curiae in various cases. He appeared for the victims of the endosulfan tragedy in the Kasargod district in Kerala. In that case the Supreme Court of India directed the Kerala government to pay compensation to the child victims.
Raj has written articles appeared in leading newspapers in India, including The Hindu, The New Indian Express, The Times of India, Deccan Herald and The Statesman, as well as journals such as Economic and Political Weekly, Frontline and Mainstream Weekly. He has also written in the law journals.
His published works in English include “Commentaries on Marumakkathayam law”, (1995, along with Ms. K.P. Suchitra) “The Spirit of Law” (2012) and “Rethinking Judicial Reforms: Reflections on Indian Legal System” ( 2017).