Motorbike sold to a person and the person didn't change the ownership.

I owned a motorbike in Delhi and due to a terrible situation I trusted a buyer from UP and sold the bike to him and handed over the RC. This was done in 2017 December month. At that time I used to check the registration details using a MVD portal from delhi traffic police and used to enter the mobile number registered with the bike. After selling it I entered my mobile number and couldn't access the portal and I believed he has done the transfer. (I understand that I was careless and didn't think it through then). In 2020 I got a meassage that this bike gotta petty case of riding without a helmet in my phone and just checked in the parivahan app and found the owner is still me. I contacted this person and asked him to change the ownership and he was behaving in a reckless manner. He told me he gave this bike to an another dealer and gave his contact. I contacted this dealer and the dealer told he don't know about this bike. I filed a complaint with delhi police and they asked me to come to Delhi. I belong to Kerala state and this bike was used when I used to work in Delhi. I couldn't go to delhi to deal with this without knowing how long it will take for this to get over. The delhi police closed the complaint saying " Now I get messages every year about this challan and it is moved to court. I need to do something about this and remove my name from this ownership. I have given him the RC and there was a sale deed in A4 paper which he igned and gave me. I cannot find it too. I am looking for some ways to clear my name out of this. I am worried if this can lead to my cancellation of licence.