After completing Graduation, Dr. Rajesh Ranjan completed his MA, M. Phil. & Ph. D. from University of Delhi, Delhi. Subsequently in the year 2001 Dr. Ranjan joined Guru Gobind Singh Department of Religious Studies, Punjabi University, Patiala as a Lecturer in Buddhism. While working in the Punjabi University, he was conferred Maharshi Badarayan Vyas Samman in the Year 2006 by the President of India for his contribution towards the dissemination and popularization of Pali and Buddhist Studies. In due course of time he was promoted to the post of Reader in the same Department.
In the year 2010, Dr. Ranjan joined as a Professor in the Department of Pali, Nava Nalanda Mahavihara (Deemed to be University under Ministry of Culture, GoI), Nalanda. During his teaching career of more than 21 years, Dr. Ranjan has to his credit several research papers published in reputed journals and five books which include edited/translated works of Pali literature into Hindi and Punjabi as well. So far more than twelve research scholars have been awarded the degree of Ph. D. under his supervision.
At Nava Nalanda Mahavidyalaya (NNM), Dr. Ranjan got opportunities to work closely with the then Director and the present Vice Chancellor and helped them in the administrative matters of the Deemed to be University related to UGC and Ministry of Culture, Govt. of India. He was also nominated / appointed as members of several Committees / Boards, such as Finance Committee, Academic Council and Board of Management for several terms in different institutions / universities including NNM, Dr. Ranjan also worked as In-charge Registrar for around ten months in NNM.