In the present work, we examine the magnetic properties of 8 "endto-end" thiocyanato, and 3 "end-to-end" cyanato double bridged Ni(II) binuclear complexes. Thiocyanato complexes are weakly ferromagnetic. Cyanato bridged complexes exhibit weak antiferromagnetic coupling. Therefore, it is a challenge for computational chemistry to calculate the exchange coupling constant in these systems accurately. 17 different Density Functional Approximations with different flavors are used to find the method of choice to study magnetic properties in binuclear Ni(II) complexes within the Broken-Symmetry approach. It is found that M06-2X and PWPB95 performed the best compared to experimental values for the entire set of examined complexes. Furthermore, the magneto-structural correlation rationalizes the results.