An aspect of the present investigation relates to the method of treating or preventing the viral diseases, cancer, or bacterial infections by administering to a subject with therapeutically effective amount of the organometallic Mn6 clusters or its pharmaceutical composition thereof. Need of the day, in this proposal, unique examples of organometallic Mn6 clusters as medicinal inorganic compounds [Mn6(μ2-L)6(CH3)6] and / or [Mn6(μ2-L)6(CO)6] {M = Mn(IV), L = synthesized Schiff base ligands; H2L1, H2L2, etc.) will be synthesized by the methanolic solution of Mn(OAc)2.4H2O and Schiff base ligands in the presence of MnO2 catalysts and Mn2(CO)10 for the developments of new therapeutic and chemotherapeutic diagnostic metallodrugs. This project describes unique examples of the synthesis and theoretical/biological evaluation of organometallic Mn6 coordination clusters intended as dual functional agents against SARS-CoV-2 (Covid-19) / HIV virus inhibition and cancer cells for innovative contributions in the bioinorganic and metal-based drug communities. The synthesized organometallic Mn6 clusters will be characterized via various physicochemical and spectroscopic methods as well as single crystal X-ray crystallography experimental techniques, cyclic voltammetry measurements and computational approaches (docking and simulations).