This study aims to identify the significance of different blood viscosity models along with different Reynolds numbers in the simulation of blood flow in a multi-stenosed Left Coronary Artery (LCA) model. Computational fluid dynamics techniques were implemented to derive the hemodynamic outcomes of the diseased three-dimensional Left Coronary Artery (LCA) models comprising of multiple stenoses. The three-dimensional LCA model was reconstructed using the angiographic images of a healthy person, and three viscosity models, i.e., Carreau, Quemada, and Modified Cross, were considered for carrying out blood flow simulation through it. In this work, the behavior of blood velocity was analyzed by increasing the level of blockage in each of the considered blood viscosity model. It is noticed that the increase in velocity is in proportion with the rise in Reynolds number. This study shows that the Quemada model records the maximum velocity magnitude with the other two rheological models for higher Reynolds numbers. In this work, the area-averaged wall shear stress (AAWSS) along the left anterior descending segment between the areas of double stenoses for different Reynolds numbers was also analyzed. Two peaks of AAWSS were seen for all the Reynolds numbers indicating the two sections of constrictions. The obtained highest peak reflects the primary blockage. Also, an emphasis is laid to prefer the Carreau model over the Quemada and Modified Cross model. This work is purely computational based that might be helpful in providing an insightful understanding of blood flow conduct at the diseased stage in the cardiovascular system.