RC Transfer Question On Sale To Dealer

I was trying to sell my old car (private 4 wheeler) in Bengaluru. The dealers were asking me to sign blank forms 29 and 30 for RC transfer. They claimed that once they find a buyer they will submit the forms to the RTO for RC transfer. I guess this is common practice. I also found that the government has another form 29C to formally notify the RTO of a used car being handed over to a dealer. However none of the Karnataka dealers seem to be registered in the government website for this. Now my questions are: 1. In the absence of form 29C what other options are available to the seller of a used car to officially record the vehicle delivery to a dealer with the RTO before forms 29 & 30 are submitted? 2. One of the dealers agreed to provide documentation noting the vehicle delivery and the fact that the dealer would complete the RC transfer once they find a new buyer. Is this along with the delivery note enough to indemnify the seller in case of any mishap?