Does the inmate have a possibility of getting out earlier then the release date

All inmates receive "good time credits" when they begin their sentence. Usually, that is 15% and that is the most it can be, it can only lessen by bad behavior. The one way for early release is if the inmate has information about another crime or criminal enterprise that would lead to the prosecution and conviction of another. THAT is also called snitching (not recommended) and it could carry repercussions on the yard, but the weak-minded always look for a short cut.