Buyer not transferring bike on his name

This is to inform you that I (Ravindra Kumar Jain s/o Kailash Chandra Jain) owner of Hero Honda Passion Plus having Chassis no - 06A09C02736, Engine no - 06A08M02595, color - Black & registration number - MH14 AR9020 has sold my bike to Rahul Yadav s/o Rajesh Yadav (Sales Manager) Kaveri Automobiles Pvt Ltd Greater Noida having address (voter id attached) as – House No - 50, Kehri, Thana - Bewar, Tehsil - Bhogaon, District Mainpuri UP PIN 206301 having voter ID no ZTI2061158 Mobile No 8447757962 in exchange of TVS Scooty Pep Plus having Engine No 0G3LE2395130 & Frame No MD626BG32E2L08939 on 10-April-2015 10:30 AM. From mentioned date and time they have taken ownership of the same and will be responsible for all RTO/Tax/Police related things. They have also taken the responsibility to get current NOC cancellation (for Gurgaon Haryana) and registration transfer to Noida or Mainpuri RTO. But he is not getting it transferred on his name, will that 100/- stamp paper will save me from future legal issues?