In Vitro antibacterial activity of ligand and its metal complexes were evaluated using Well disc & Diffusion method and compared to the standard drug like Amikacin, Ceftriaxone, Gentamycin and Levofloxacin. The antibacterial activity was examined against Escherchia Coli (E-Coli) as gram negative bacteria (GNB) and Bascillus Subtilis as gram positive bacteria (GPB).Tested complexes followed the order in GPB and GNB :[Cu(L)2Cl2] > [Cu(L)2Br2] > Ligand and the antibiotic followed the order in GPB and GNB: Ceftriaxone >Amikacin > Levofloxacin and Gentamycin resisted. The Minimum Inhibition Concentration (MIC) or Zone of Inhibition (ZI) diameter in the range of 6-20 mm and clearly explained by Conceptual Model of Inhibition (CMI), Tweedy’s Chelation Theory (TCT) and Overton’s Concept Theory (OCT).