Ferrimagnetic (FiM) materials have attracted much attention owing to their dynamic magnetization capacity, which has potential applications in spintronics. Herein, electronic and magnetic properties of Lu2NiIrO6 double perovskite oxide are investigated under the effect of Ca-doping at Lu site using ab-initio calculations. It is established that the undoped system is FiM Mott-insulator with an energy band gap of 0.20 eV, which is attributed to a strong antiferromagnetic (AFM) interactions between high energy half-filled Ni+23d8 (eg2↑ eg0↓) and low energy partially filled Ir+45d5 (t2g3↑ t2g2↓) ions. The structural and dynamical stability of the doped system is confirmed by computing the formation energy and phonon dispersion bands, respectively. The analysis of magnetic ordering by comparing FiM, ferromagnetic, and AFM energies of the Ca-doped Lu2NiIrO6 system reveals that FiM ordering is the ground state alike the undoped case. A half-metallic behavior is obtained for Ca-doped system, because the admixture of Ir 5d orbitals in the spin majority channel is primarily responsible for conductivity. Moreover, a substantial enhancement in the magnetic moment on one of the Ir ions is also observed due to the reduction of Ir-O hybridization.