The Benue-Congo branch of the Niger-Congo language family is primarily spoken in several regions of West and Central Africa. Here are the key areas where these languages are predominantly used:

1. Nigeria: This is the most significant area for Benue-Congo languages. Major languages include Yoruba, Igbo, and various other ethnic languages such as Tiv and Ebira. The languages are spoken across various states, particularly in the southwestern and central regions.

2. Cameroon: In Cameroon, languages such as Bantu and other related languages are part of the Benue-Congo group. The regions of the Southwest and Littoral are notable for their linguistic diversity.

3. Democratic Republic of the Congo (DRC): The DRC is home to a large number of Bantu languages, which fall under the Benue-Congo branch. Languages like Lingala, Kikongo, and Swahili (in its local dialects) are widely spoken.

4. Central African Republic: Some languages in the Central African Republic also belong to the Benue-Congo category, particularly in the southeastern regions.

5. Gabon and Republic of the Congo: In these countries, Bantu languages are spoken, particularly in rural areas.

6. Equatorial Guinea: The Fang language, which is part of the Benue-Congo family, is spoken in this region.

The Benue-Congo languages are characterized by a rich diversity of dialects and variations, reflecting the complex ethnic and cultural landscapes of these regions.

If you would like more specific information about a particular language or area, feel free to ask!