the spin only magnetic moment of [MnBr₄]^2- is 5.9 BM.predict the geometry of the complex ion ?

Since the coordination number of Mn²⁺ ion in the complex ion is 4, it will be either tetrahedal or square planner. But the fact that the magnetic moment of the comlex ion is 5.9BM, it should be tetrahedral in shape rather than square lanner because of the presence of five(5) unpaired electrons in the d orbitals.