1. Power on both your RCA DVD player and the URC-R6 remote.
2. Press and hold the "TV" button on the remote until the red light above the button stays lit.
3. Press the "DVD" button on the remote.
4. Enter the three-digit code for the RCA DVD player. You can obtain the codes by consulting your remote's user manual or by searching for the codes online.
5. Press the "Enter" button on the remote.
6. Once the red light flashes twice, programming is complete.
Test the remote by pressing various buttons to ensure they control the RCA DVD player as expected. If any button doesn't work properly, repeat the programming steps for that specific button.
Note that some RCA DVD players may require a different programming sequence or remote control code. If the steps provided don't work, refer to the specific instructions provided in the user manual of your RCA DVD player or universal remote.