Before joining AU he was a postdoctoral fellow with Tel Aviv University, Israel and Tata Institute of Fundamental Research (TIFR), Mumbai. Ratnik obtained his PhD and MTech in Information and Communication Technology from Dhirubhai Ambani Institute (DA-IICT), Gandhinagar, in 2011 and 2005 respectively, and his BE in Computer Engineering from Dharamsinh Desai University, Nadiad, in 2002.