The correct procedure would be to wait for the car to certified as total lost by insurance company.
By then, you will need send the vehicle to the nearest Puspakom inspection centre for plate number transferring inspection.
You will need to register a new car number plate for the total lost vehicle, and transfer out the old number.

Usually in this case, you must transfer the old number plate to a new vehicle within a month time frame. Falling to do so, u might lose the number forever, go JPJ and appeal for extension? You can try that.

If u thinking to hold the number for several months, transfer it to a motorcycle.

The expenses to tow the car to Puspakom for inspection, a new number for the wreck and all sort of fee, shall be bear by your side.