The present disclosure described heterocyclic compoundsof Formula I or,its stereoisomers, pharmaceutically acceptable salts, complexes, hydrates, solvates, tautomers, polymorphs, racemic mixtures, optically active forms and pharmaceutically active derivative thereof and pharmaceutical compositions containing them as the active ingredient. The present disclosure also describes the synthesis and characterization of aforementioned compoundsto exhibit high anticancer activity. The compounds of the present disclosure are useful as medicaments and their use in the manufacture of medicaments for treatment, prevention or suppression of diseases, and conditions mediated by one or more BET family of bromodomains.
