Estimation of pharmacotherapeutic potential, possible molecular mechanism of action, toxic/side effects and interaction with drug-metabolizing enzymes was achieved by computational studies. Computer assisted drug designing involves all computational techniques to discover, design and optimize biologically active compounds with desired structure features for putative use as drug. The Molecular Docking studies of 2-substituted-6(4-methylphenyl)-4,5-dihydropyridazin-3(2H)-ones and 3-substituted-6(4-methylphenyl)-4,5-dihydropyridazin-3(2H)-ones and pyridazine substituted triazin was carried out using Molegro Virtual Docker for determination of anti-inflammatory activity using (PDB ID: 6COX) and analgesic activity using (PDB ID: 1CX2). The novel derivatives obtained were subjected to docking against the selected proteins and the potent derivatives of pyridazinone were finally selected on the basis of Mol Dock score values. The in-silico docking results showed that compound XIV i.e. N-(4-(2-imino, 3,4,8,9-tetrahydro-2H-pyridazin [1,6-α][1,3,5 triazin-7-yl)phenyl)-methanesulfonamide exhibited relatively comparable binding affinity with highest Mol Dock Score value of -125.066 and formed four H-Bonds comparable to standard compound having Mol Dock Score of -86.155 on docking with (PDB ID: 6COX) and possessed highest Anti-inflammatory activity. The compound XVII i.e. 2-(4-benzylphenyl)-3,4,7,8-tetrahydropyrimdo[1,6-b]pyridazine-6-imine exhibited highest binding affinity with Mol Dock Score value of -103.947 and formed four hydrogen bonds comparable to standard compound value having Mol Dock Score -119.837 with (PDB ID: 1CX2) and possessed highest Analgesic activity. Some other compounds which showed better results are compounds XII, XVI, XIII, VIII with anti-inflammatory activity and compounds XX, XXIII, XI, VIII with analgesic activity. The SAR studies shows that the compounds XIII and compounds VIII showed good mol dock score bearing pyridazinone as central /basic moiety having sulphate group substituttion on sixth position while the compounds II and III having pyridazinone as central moiety but having hydrazine hydrate substitution on fifth position having poor docking results for anti-inflammatory and analgesic. Thus, pyridazinone-based compounds represent potential lead compounds for further development of selective COX inhibitors.