Get one DVD rental at Redbox for free with code M6FR97. Valid through 11:59pm central time on 4/20. Find a Redbox Location near you here. To use the code, select Rent with Promotion on the first screen and simply remember to return the DVD by 9pm the next day. You can use 1 code for each debit/credit card. To rent multiple movies, just re-use the code with each card.