[en] We have investigated the optical and transport properties of double perovskite ${\mathrm{L}\mathrm{a}}_2{\mathrm{C}\mathrm{r}\mathrm{M}\mathrm{n}\mathrm{O}}_6$ (LCMO) synthesized by auto combustion sol-gel method. The single phase formation with orthorhombic structure having $Pbnm$ symmetry has been confirmed by Rietveld refinement of x-ray diffraction (XRD) pattern. The particle size has been calculated from Debye Scherer formula and scanning electron micrograph (SEM). The elemental composition has been checked using energy dispersive x-ray (EDX) spectroscopy. The infrared (IR) reflectivity spectrum has been measured in the frequency range of 30–7500 cm⁻¹ at near normal incidence at room temperature. We observed only eight well resolved phonon modes. Indirect optical band gap ∼0.96 eV has been estimated using Tauc relation from UV-visible absorption spectrum. The DC electrical resistivity measurement suggests small polaronic hopping above room temperature. The temperature and frequency dependent AC dielectric measurements and the value of activation energy support semiconducting nature of the material. (paper)