Complex sentence: After serving in various capacities in BARC, he headed the organisation as the Director during May 2010 to April 2012 before taking over as Secretary, Department of Atomic Energy and Chairman, Atomic Energy Commission of India till his superannuation in October 2015.
Split into simpler sentences: After serving in various capacities in BARC, he headed the organisation as the Director during May 2010 to April 2012. He served as Secretary, Department of Atomic Energy and Chairman, Atomic Energy Commission of India from May 2012 till his superannuation in October 2015.