Cr-based superconductors provide a playground to understand the pairing mechanism in unconventional superconductor as they are strong candidate for multiband triplet pairing state. Recently, Mu et al. reported a new quasi-one-dimensional superconductor Na2Cr3As3 with transition temperature, Tc, of 8.6 K (Phys. Rev. Mat. 2, 034803 (2018)), to date this is the highest reported Tc in a, A2Cr3As3 (A: Rb, Cs, K), Cr-based superconductor. Smaller value of electronic heat capacity jump 0.69 below par for a BCS superconductor (= 1.43), which suggests the possibility of an unconventional nature to the superconductivity. Recently we have published two papers on musr studies of A2Cr3As3 (A=K and Cs, PRB(2015) & JPSJ (2017)). We plan to perform the MuSR study, both transverse field and zero field to understand pairing mechanism in Na2Cr3As3 and compare them to the K and and Cs based compounds.