The mutual influence of two mesogenic components, namely a nematic liquid crystal N-(p-methoxy-bezylidene)-butylaniline (MBBA) and a lyotropic liquid crystal poly-(phenyl-methacrylic) ester of cetyloxybenzoic acid (PPMAECOBA) in tetra-chloromethane (TCM) is studied in this paper. The ordinary and extraordinary refractive indices of the mixtures, nematic liquid crystal and lyotropic liquid crystal were measured at 589.3 nm with a Rayleigh interferometer and some electro-optical parameters were computed. The main refractive indices, the birefringence, the main normalized polarizabilities and their difference are dependent on the mixture volumetric concentrations, proving the existence of the collective orientational interactions between the two types of liquid crystals.