Intimate incomplete transfer of vehicle?

My father sold a bike few years back to a guy we know. But he didn't make sure that the guy got it transferred at the RTO. So the papers and the bike are still with the guy, but the ownership is still on us.

Now my father is not in a state to take action, and I'm not currently in the the city.

Is there any way to intimate the RTO declaring we're no longer responsible for this vehicle?

I found a link on the RTO site: https://tgtransport.net/TGCFSTONLINE/Reports/VehicleTransferIntimation.aspx

Can anybody also confirm if it's for this purpose or not?