Sailesh has taken over as Registrar General and Census Commissioner, India in the Ministry of Home Affairs, Government of India on 12th January, 2016. He belongs to Indian Administrative Service, 1985 batch, Assam-Meghalaya (RR). Earlier he was Additional Secretary in the Ministry of Home Affairs, Government of India. He has also worked in the Ministry of Youth Affairs and Sports, Department of Heavy Industries, Ministry of Power and Ministry of External Affairs.
He has also served as Principal Secretary, Home & Political in the Government of Assam during 2012-14. Sailesh holds a Masters Degree in Economics from Delhi School of Economics (1982). He has also done Post Graduation in Management from MDI, Gurgaon (1993). He is an alumnus of Graduate Research Institute for Policy Studies (GRIPS), Tokyo, Japan where he did his Masters in International Development Studies (2003)