He is the former Municipal Commissioner and Administrator of Brihanmumbai Municipal Corporation (BMC) and is former Additional Chief Secretary in the Maharashtra Chief Minister's office. Prior to this, Chahal has served Government of Maharashtra and India in various capacities. In 2021, he was awarded an honorary degree of Doctor of Science (Honoris Causa) honorary doctorate by his alma mater, Thapar Institute of Engineering and Technology (TIET), during a special convocation at its Patiala campus for his role in handling the Covid-19 crisis in Mumbai. In his initial career he was collector of Thane and Chatrapati Sambhajinagar districts, later on he was Joint Secretary in Ministry of Home Affairs, Ministry of Women & Child Development and Ministry of Panchayati Raj. Following that he was also Principal Secretary in Water Resources Department and Urban Development Department of Maharashtra. Post retirement, he is serving as the Chairman of the Mumbai Police Housing Township Project for a period of five years.
He added thousands of beds through new field hospitals, and private facilities handed over their COVID-19 wards to the government with 800 vehicles being turned into ambulances. A proactive approach was used to focus on 55 slums including, Dharavi, where a strict lock-down was accompanied by aggressive sanitation of public toilets, mass coronavirus screening and a huge volunteer effort to ensure that nobody went hungry. All positive test reports in Mumbai were routed through "war rooms".
1234"Executive record sheet". Supremo - Department of Personnel and Training, Ministry of Personnel, Public Grievances and Pensions, Government of India. Archived from the original on 10 May 2021.