The tunable microwave absorbers are used to combat the electromagnetic pollution created by the development of high speed electronic devices. In the present paper, we report microwave absorption characteristics of M-type Ba_0.5Sr_0.5Co_xTi_xFe_12-2xO₁₉ (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) hexaferrite-Polyaniline based composites were prepared by using standard ceramic method. X-ray diffraction analysis of prepared compositions revealed the formation of M-phase along with minor traces of hematite in substituted compositions. The quarter wavelength and impedance matching mechanism were used to evaluate microwave absorption from 8.2 to 12.4 GHz using vector network analyzer. The substitution of Co²⁺ and Ti⁴⁺ ions enhances absorption, bandwidth and improves impedance matching required for absorption.