Answer
Please see the work below.
Work Step by Step
$4d^{6}$ configuration means 6 electrons in the 4d subshell. The 4d subshell consists of 5 degenerate orbitals. Its configuration is $4d_{xy}^{2}4d_{yz}^{1}4d_{xz}^{1}4d_{x^{2}-y^{2}}^{1}4d_{z^{2}}^{1}$.