Motor Accident and false alligation

Yesterday on 15/09/2024, a boy from our own town on a bike came at high speed on the wrong side and hit the scooter that my father and sister were traveling on. He did not even had a helmet. As a result, My father got a right hand thumb finger fractured and the younger sister's leg was slightly injured. The bike rider had scratch marks on his hand and stomach. Due to this accident two mirrors of my father's scooter were broken, exhaust was cut and oil pipe was broken and some scratches. His bike had a little scratches, that's all. Even so, my father said that the boy was scared and young so we are not going to file a police complaint. Then, My father asked his known mechanic about the repair cost in front of that boy and that boy agreed and paid the repair cost ( of rs 10000) through online payment. If this is yesterday's issue, today on 16/09/2024 his mother came to us and as informed by someone who knows her, they discussed that they will do the repair by themselves at where my father requested them to get his scooter repair should be done and they going to pay for it. We also agreed and gave them our vehicle. They have taken it for repair . We haven't sent his money back its still with us. we will pay them when our vehicle gets fixed. Another story is that his mother started spreading false news that my father came in the wrong side and he hit her son's bike. also she saying my father asking 10000rs that too for an old scooter to her neighbors.. Now the point I want is, What kind of legal actions that we can take against them, is there any legal action for defaming us? Please let me know. This incident is new to us so we don't know what to do. There is a photo proof of his bike and my father's scooter with us. If so please let me know whether it is possible to register a complaint or what actions or moves that we can take next?