The present disclosure provides a multi-metallic catalyst system comprising at least one support, and at least one promoter component and an active component comprising at least two metals uniformly dispersed on the support. The present disclosure also provides a process for preparing the multi-metallic catalyst system. Further, the present disclosure provides a process for preparing upgraded fuel from biomass. The process is carried out in two steps. In the first step, a biomass slurry is prepared and is heated in the presence of hydrogen and a multi-metallic catalyst that comprises at least one support, at least one promoter component, and an active component comprising at least two metals to obtain crude biofuel as an intermediate product. The intermediate product obtained in the first step is then cooled and filtered to obtain a filtered intermediate product. In the second step, the filtered intermediate product is hydrogenated in the presence of the multi-metallic catalyst to obtain the upgraded fuel. The fuel obtained from the process of the present disclosure is devoid of heteroatoms such as oxygen, nitrogen and sulfur.