A group of chickens is commonly referred to as a “flock” or a “clutch.” However, there are specific terms for different types of chicken groups:
Brood: A brood refers to a group of chicks hatched and raised together by a mother hen.
Peep: This term is sometimes used to describe a group of baby chickens.
Roost: A roost is a group of chickens gathered together to rest or sleep, typically on a perch or in a designated area within a coop.
Charm: Though less common, some people use the term "charm" to describe a group of chickens.The specific term used may vary by region and context, but “flock” is the most widely recognized and used term to refer to a group of chickens.
Chickens on Wikipedia: