Diwan was born in Village Sunnam, Tehsil Pooh, District Kinnaur, H.P., India, in 1975 and studied at the Government High School, Giabaung, Tehsil Pooh, Distt. Kinnaur, H.P. from 1980 to 1995. He graduated with a B.A. (Hons) in Public Administration in the year 2000 and earned an M.Phil. in Economics from Punjab University, Chandigarh, in 2005.

From 2010 to 2017, Diwan served Deer Park Institute in the area of Administration and Finance and, in 2017, was appointed his current position as Director of Deer Park by Siddhartha’s Intent Society India.