From the Tivo help page on Netflix at http://support.tivo.com/app/answers/detail/a_id/266
How do I turn on Closed Captioning for Netflix videos?
1. Locate the video you wish to watch and push SELECT.
2. Arrow down to Audio and Subtitles and push SELECT.
3. Arrow down to your preferred language under Subtitles.
If you have an issue with this or your language is not provided, contact Netflix Customer Support for assistance.