HB 686 is a designation used by multiple states for different pieces of legislation, so the answer depends entirely on which state you are asking about. Without knowing the state, it is impossible to give you an accurate answer about what the bill covers or how it affects inmates.
If you can provide the state, that narrows it down immediately. Alternatively, you can search for the bill directly through the relevant state legislature's website, where all introduced and passed legislation is catalogued by bill number and session year. Most state legislature websites have a search function where typing HB 686 along with the state name will pull up the full text, sponsor information, and current status of the bill.
If this is related to a federal inmate and you believe it is a federal bill, the Library of Congress website at congress.gov is the most comprehensive source for federal legislation by bill number.
Once you have the state confirmed, feel free to ask again and we can give you a more specific answer about what the legislation does and how it might affect someone who is incarcerated.