RTA Hyderabad — Sold my bike in Sept 2019 still buyer haven't transferred on to his name

I Raj Shekar sold my bike (pulsar 200ns) on September 11th, 2019 to Mr. Motilal Kumar (cont. No. [protected]) after selling I called him several times and told to transfer the vehicle in his name and I requested for his aadhaar card but he didn't share and not even shared his address proof. I got three challans to my address recently when I called him he told me that he sold it to one of his friend Name Mr. Rupesh (contact no. [protected]) when I called Rupesh he just hangs up the call