He has already worked as Executive Director (Legal) with Sebi during the periods 2008-2011 and 2011-2014.
"Ranganayakulu has joined as Executive Director (Legal) in the Securities and Exchange Board of India (Sebi) today, for a period of three years," the regulator said in a statement.
Among other executive directors are Ananta Barua, P K Nagpal, S Ravindran, R K Padmanabhan, Gyan Bhushan and S V Murali Dhar Rao.