File Extension RAC File Format Subtitling file format RAC stands for Subtitling file format. This was last updated in March 2012 By Margaret Rouse Browse File Extensions Alphabetically: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Ask a Question. Find an Answer. Ask your peers a question about this file extension. Ask a Question RAC and parallel server What is the format of a SoftNI SUB file? Can I install Oracle binary files on a SAN?