Since the pandemic, a plethora of studies have focused on finding suitable therapeutic remedies for Covid-19, and the search is still ongoing. Among several possible targets, including spike protein, main protease (M pro ), etc., RdRp is a promising target for drug design. Some antiviral molecules have already been identified by targeting key residues in the active site of RdRp and other proteins involved in the lifecycle of the virus. At the same time, various drug repurposing studies that target RdRp using computational tools like docking have also been reported. All these studies resulted into a great number of possible drugs which could be repurposed for the treatment of Covid-19, pending rigorous theoretical or experimental tests. However, the search for a cure for Covid-19 is far from over. Among the possible drugs for Covid-19 that target RdRp, Remdesivir is the one with FDA approval. Although the effectiveness of Remdesivir is still disputed, there have been many studies on its inhibition effects . It was found by experimental and computational studies that the active form of Remdesivir, Remdesivir triphosphate (RTP), is an effective drug that prevents the replication of RNA at the active site of the RdRp. Studies indicate that the binding affinity of RTP is in the range of ~5 kcal/mol to ~7 kcal/mol , and it completely inhibits the polymerization process at the catalytic site. In the present study, we used an atomistic receptor-based de novo generation algorithm followed by structural mapping and free energy calculations to obtain a new set of molecules and repurpose drugs that can possibly bind more effectively than the RTP. Initially, we analyzed the active region of RTPbound 3D structure of RdRp for identifying the hotspot region, which was used as the target location for generating small molecules. To confirm the binding, we have performed molecular dynamics simulation and free energy calculations to compare the binding strength of our de novo molecules and RTP. From the multi-dimensional free energy surfaces, we found five molecules, some of which are known drug molecules, that can bind more strongly than RTP at the catalytic site of RdRp.