"住在牢房或小室中" can be translated into English as "live in a prison cell or a small chamber".
Here, "prison cell" specifically refers to a confined space in a prison where an inmate lives, while "small chamber" is a more general term for a small, enclosed room, which can be applied to various contexts, including a small, cramped living space. If the context is strictly about imprisonment, "live in a prison cell" would be the most accurate expression. If the intention is to convey a sense of living in a cramped or confined space more generally, "live in a small chamber" (or alternatives like "live in a cramped quarters" or "live in a confined space") could also be used.