In this work, magnetic and transport properties of LaSrMnRuO6 are studied in detail. Absence of superlattice peak ~19° in X-ray diffraction pattern indicates the Mn/Ru disorder at B-site, known as B-site disorder. ZFC curve exhibits a weak ferromagnetic transition around 𝑇_𝐶1~223 K, followed by a cluster glass transition at 𝑇𝐶2~32 K, validated by frequency-dependent ac susceptibility studies. The high-temperature Curie-Weiss fit, along with the S-shape of the M-H hysteresis loop at 300 K, indicates the presence of short-range ferromagnetic correlations above T_C. Resistivity follows the small polaron hopping (SPH) model in the 118 K-380 K temperature range, yielding a room temperature conductivity of 3.02 S/cm, which suggests semiconducting-like behaviour at room temperature. Temperature-dependent magnetoresistance (MR) displays anomalies near ~230 K and 30 K corresponding to the ferromagnetic transition (T_C1) and low-temperature cluster glass transition (T_C2), respectively. Field-dependent MR shows a sharp increase at low fields below the cluster glass temperature, which suggests spin-polarised inter-cluster tunnelling of charge carriers. The gradual linear increase in MR with the applied magnetic field at high temperature is attributed to the intrinsic suppression of spin-disorder scattering induced by the B-site disorder. Absence of signature corresponding to T_C2~32 K in the C_p vs T curve, further supports cluster glass behaviour.