Buyer not transferring bike in his name sold in December 2019

I had sold my bike to a buyer in December 2019. The buyer at that time, after taking my signature on all the relevant RTO documents, had assured me that he will transfer the bike in his name. Around August 2020, this bike that was sold by me to this buyer was involved in some sort of an accident because of this, the police had approached my landlord's office as I was not available. After my landlord's lawyer informed me that such and such had happened, I came to know that the bike had still not been transfered. I spoke to police officer in charge of the accident case and he upfront told me that he knows I sold the bike and I am not involved in the case at all. I spoke to the buyer and informed him about this incident and requested him again to transfer the bike in his name. He assured me that he will do it. Now, this month I have received a notice from Lok Adalat that I have not paid the traffic penalty fines for that bike. I again spoke to the buyer after receiving the Lok Adalat notice and informed him and told him to transfer the bike on his name. He again said that he will transfer the bike. I have recorded the call. I just want to know what is the legal remedy available for me to avoid getting involved in police and legal hassles again for a bike that I have already sold nearly 2 years ago