A compound of Formula I or its stereoisomers, pharmaceutically acceptable salts, complexes, hydrates, solvates, tautomers, polymorphs, racemic mixtures, or optically active forms, wherein R 1 is selected from the group consisting of C 1 - 6 alkyl, C 2 - 6 alkenyl, C 3 - 6 cycloalkyl, C 1 - 6 alkylamino, C 1-6 aminoalkylene, 4-7 membered carbocyclyl or heterocyclyl ring which may be fully saturated or unsaturated or partially unsaturated optionally having up to three heteroatoms independently selected from O, N, or S, each of which is unsubstituted or substituted with 1 to 3 groups independently selected from halogen, amino, hydroxyl, C 1-6 alkoxy, SO 3 H, SO 2 R 9, COOR 9, CONHR 9, or SO 2 NHR 9, wherein R 9 is selected from H, C 1-6 alkyl, methylsulfone, C 1 - 6 alkyl, OC 1 - 6 alkyl, OC 1 - 6 haloalkyl, C 3 - 6 cycloalkyl, 3-7 membered heterocyclyl ring which may be fully saturated or unsaturated or partially unsaturated optionally having up to three heteroatoms independently selected from O, N, or S, C 3 - 6 cycloalkylamino, C 3 - 6 aminocycloalkyl, C 1 - 6 alkylamino, or di (C 1 - 6 alkyl)amino; R 2 and R 3 are independently selected from the group consisting of hydrogen, C 1 - 6 alkyl, fluorine, OC 1 - 6 alkyl, hydroxyl, and amino; R is selected from the group consisting of hydrogen, fluorine, cyano, OC 1 - 6 alkyl, and hydroxyl; X 1 is N, or CR 4; R 4 is selected from the group consisting of hydrogen, halogen, cyano, -OC 1 - 6 alkyl, C 1 - 6 haloalkyl, -OC 1 - 6 haloalkyl, and C 1 - 6 alkyl; X 2 is N, or CR 5; R 5 is selected from the group consisting of hydrogen, halogen, cyano, -OC 1 - 6 alkyl, C 1 - 6 haloalkyl, -OC 1 - 6 haloalkyl, and C 1 - 6 alkyl; X 3 is N, or CR 6; and X 4 is CH, or C-C 1 - 6 alkyl when dotted line (—) represents a bond, wherein R 6 is selected from the group consisting of hydrogen, halogen, cyano, -OC 1 - 6 alkyl, -OC 1 - 6 haloalkyl, and C 1 - 6 alkyl, wherein C 1 - 6 alkyl is optionally substituted with hydroxyl, or amino; X 4 is CH 2, or O; and X 3 is CH 2 when dotted line (---) represents no bond; n 1 is 0, or 1; n 2 is 0 to 2; Y 2 and Y 3 are independently selected from -N, or CR 7; R 7 is selected from the group consisting of hydrogen, halogen, cyano, -OC 1 - 6 alkyl, C 1 - 6 haloalkyl, -OC 1 - 6 haloalkyl, and C 1 - 6 alkyl; Z 1 is selected from the group consisting of O, S, and CH 2; and R 8 is selected from the group consisting of hydrogen, C 1 - 6 alkyl, and fluorine. or its stereoisomers, pharmaceutically acceptable salts, complexes, hydrates, solvates, tautomers, polymorphs, racemic mixtures, or optically active forms, wherein R 1 is selected from the group consisting of C 1 - 6 alkyl, C 2 - 6 alkenyl, C 3 - 6 cycloalkyl, C 1 - 6 alkylamino, C 1-6 aminoalkylene, 4-7 membered carbocyclyl or heterocyclyl ring which may be fully saturated or unsaturated or partially unsaturated optionally having up to three heteroatoms independently selected from O, N, or S, each of which is unsubstituted or substituted with 1 to 3 groups independently selected from halogen, amino, hydroxyl, C 1-6 alkoxy, SO 3 H, SO 2 R 9, COOR 9, CONHR 9, or SO 2 NHR 9, wherein R 9 is selected from H, C 1-6 alkyl, methylsulfone, C 1 - 6 alkyl, OC 1 - 6 alkyl, OC 1 - 6 haloalkyl, C 3 - 6 cycloalkyl, 3-7 membered heterocyclyl ring which may be fully saturated or unsaturated or partially unsaturated optionally having up to three heteroatoms independently selected from O, N, or S, C 3 - 6 cycloalkylamino, C 3 - 6 aminocycloalkyl, C 1 - 6 alkylamino, or di (C 1 - 6 alkyl)amino; R 2 and R 3 are independently selected from the group consisting of hydrogen, C 1 - 6 alkyl, fluorine, OC 1 - 6 alkyl, hydroxyl, and amino; R is selected from the group consisting of hydrogen, fluorine, cyano, OC 1 - 6 alkyl, and hydroxyl; X 1 is N, or CR 4; R 4 is selected from the group consisting of hydrogen, halogen, cyano, -OC 1 - 6 alkyl, C 1 - 6 haloalkyl, -OC 1 - 6 haloalkyl, and C 1 - 6 alkyl; X 2 is N, or CR 5; R 5 is selected from the group consisting of hydrogen, halogen, cyano, -OC 1 - 6 alkyl, C 1 - 6 haloalkyl, -OC 1 - 6 haloalkyl, and C 1 - 6 alkyl; X 3 is N, or CR 6; and X 4 is CH, or C-C 1 - 6 alkyl when dotted line (—) represents a bond, wherein R 6 is selected from the group consisting of hydrogen, halogen, cyano, -OC 1 - 6 alkyl, -OC 1 - 6 haloalkyl, and C 1 - 6 alkyl, wherein C 1 - 6 alkyl is optionally substituted with hydroxyl, or amino; X 4 is CH 2, or O; and X 3 is CH 2 when dotted line (---) represents no bond; n 1 is 0, or 1; n 2 is 0 to 2; Y 2 and Y 3 are independently selected from -N, or CR 7; R 7 is selected from the group consisting of hydrogen, halogen, cyano, -OC 1 - 6 alkyl, C 1 - 6 haloalkyl, -OC 1 - 6 haloalkyl, and C 1 - 6 alkyl; Z 1 is selected from the group consisting of O, S, and CH 2; and R 8 is selected from the group consisting of hydrogen, C 1 - 6 alkyl, and fluorine.