One of the most elusive unsolved problems of today is Riemann hypothesis. For long mathematicians have struggled to prove this problem, and also tried to devise an elementary version of the problem, proof of which indirectly proves Riemann hypothesis. In 2002 J. C. Lagarias published such an elementary version of the hypothesis which has been widely accepted as an elementary equivalent of Riemann hypothesis. This article attempts to prove Lagarias's condition, a proof of Guy Robin's inequality has also been provided in the end, any of which consequently proves Riemann hypothesis.