The magnetic and electronic properties of zGNR with 5-7 LD can be engineered through the variation of the width of zGNR and the position of LD. Ferromagnetic behaviour in zGNR can be found by introducing 5-7 LD close to one edge of the ribbon. Semi-metallic to semi-metallic semiconductor transition occurs by increasing the width of the ribbon or by changing the position of the LD. There is significant effect of the doping on the degeneracy of the spin states of 4-4-LD-zGNR. The transport properties calculation of N-doped 4-4-LD-zGNR reveals that it has high spin filtering efficiencies.