When we need to maintain order or check something from becoming chaotic, we often use the phrase "keep under control". There are several other synonyms for this that you can use to make your language more diverse. For example, "restrain" is an effective substitute that implies holding back from something. "Manage", on the other hand, conveys the idea of leading or supervising in a more positive way. "Regulate" implies stricter control and may be used in a more bureaucratic context. "Constrain" is useful for expressing limits on behavior. Lastly, "govern" suggests that a person or group is in charge of regulations that must be enforced.