New series of mononuclear octahedral Ru(III) complexes of general formula [RuL^1-3Cl]Cl₂ (1-3) where L = dianion of Schiff bases namely: 2,2'-(((1E,1'E)-thiophene-2,5-diylbis(methaneylylidene))bis(azaneylylidene))diphenol (H₂L¹), 2,2'-(((1E,1'E)-thiophene-2,5-diylbis(methaneylylidene))bis(azaneylylidene))dibenzenethiol (H2L2) and 2,2'-(((1E,1'E)-thiophene-2,5-diylbis(methaneylyli-dene))bis(azaneylyli-dene))-dibenzoic acid (H₂L³), respectively are synthesized and characterized by different physico-chemical techniques. The results of interaction of complexes with CT-DNA supported that, the Ru (III) complexes bind to DNA via an intercalative mode. The interaction has also been investigated by gel electrophoresis. Interestingly, it was found that all Ru(III) complexes cleave super coiled (SC) pUC19 plasmid DNA efficiently in the absence of an external agent. Further, the antiproliferative activity of the complexes on Human Cervical Cancer Cells (HeLa) and Human Breast Cancer Cells (MCF-7) were evaluated by MTT assay, which revealed that, all the complexes showed more intense inhibition against HeLa and MCF-7 cell lines, particularly Ru(III) complex (3) attenuated the strongest proliferation, allowing its use as chemotherapeutic agent for cancer treatment.