Hexagonal iridate Na2IrO3 has recently been proposed as a candidate material to exhibit strong spin-orbit coupling effects which may stabilize a Mott insulating state with unusual properties, attributed to the mixing of spin with orbital states and the special lattice topology that allows complex transfer integrals between sites. This is expected to stabilize a so called novel topological insulator, with a band gap in the bulk and metallic conduction on the surface. Here we propose to search for excited crystal field and spin-orbit energy levels of the Ir4+ ions to test the proposed conjecture for a ground state doublet with an effective J_eff=1/2 and also measure the magnetic low energy dynamics due to frustrated antiferromagnetic nearest and next nearest neighbour couplings on the Ir honeycomb lattice.