Find the number of ${\mathrm{t}}_{2\mathrm{g}}$ electrons in ${\left[{\mathrm{NiF}}_6\right]}^{2–}$

Oxidation state of Ni in [NiF₆]^-2 ,is +4. Outer electronic configuration of Ni is 4s² 3d⁸ and Ni⁴⁺ has 3d⁶. Number of electrons in t_2g is 6 and in e_g is 0.