Hon’ble Justice Manmohan, Chief Justice of the Delhi High Court, enrolled as an advocate with the Bar Council of Delhi in 1987. He practiced primarily in the Supreme Court of India and the High Court of Delhi, specializing in Civil, Criminal, Constitutional, Taxation, Arbitration, Trademark, and Service litigation. He also served as a Senior Panel Advocate for the Government of India in both the Delhi High Court and the Supreme Court of India.

Designated as a Senior Advocate by the Delhi High Court on January 18, 2003, he handled various significant cases in his private practice, involving high-profile matters related to corporate disputes, taxation issues, and property encroachments. He has delivered several significant judgments, particularly concerning the rights of economically weaker sections, children's rights to education, and issues of human trafficking.

He has a strong interest in extra-judicial activities and has actively participated in and addressed various national and international seminars and conferences. His judgments on dynamic injunctions, computation of damages in trademark matters, and legal recognition of children's rights to use their mother’s surname in official documents are considered pioneering precedents.