Filing a false FIR when the vehicle was actually sold and scrapped is illegal under Indian law (punishable under Section 217 / Section 248 of Bharatiya Nyaya Sanhita, formerly IPC Sections 182 and 211). If police investigate your complaint, perform an National Crime Records Bureau (NCRB) verification, or locate the video evidence/dealer, you could face criminal prosecution for perjury and reporting false information to a public servant.
Since you sold the bike to an unorganized scrap dealer without receiving an official Certificate of Deposit (CoD) or chassis cutout, standard online processing is blocked. However, under Section 55 of the Motor Vehicles Act, 1988, you can apply for manual cancellation of registration due to vehicle destruction.
You may prepare a notarized affidavit on non-judicial stamp paper stating that the vehicle is completely destroyed, no longer exists physically, and will never be driven on public roads and that you undertake full personal responsibility for any future liability and confirm no court cases, insurance claims, or loans are pending against it.
Along with the affidavit you submit an application to the concerned RTO by complying with necessary formalities in this regard and request for the desired relief.
If the RTO formally accepts your written application with documents but delays cancellation, keep the stamped receipt permanently. That acknowledgment serves as your legal protection against future liabilities or misuse.