First-principle calculations on structural, electronic, magnetic, and transport properties of novel Co2TaSi and Co2TaGe Heusler compounds have been accomplished successfully. The structural optimizations and cohesive energies confirm the stability of these alloys in Fm-3m phase as well as deliver the equilibrium lattice parameters. Modified Beckhe Johnson scheme predicted more efficient results than the generalized gradient approximation in defining the electronic structure and ground state properties. From the band structure analysis and density of state calculations together with spin magnetic moments, half-metallic character is anticipated with an indirect spin-down gap of 0.84eV for Co2TaSi and 1.04eV for Co2TaGe. Seebeck coefficients and electrical conductivities are calculated to envisage the possible thermoelectric response of these materials.