What is Racial, religous, national, or political groups smaller than and differing from the larger controlling group of which it is a part

The term you are looking for is "minority group." A minority group is a group of people who are smaller in number than the larger controlling group, and who differ from that group in terms of their race, ethnicity, religion, nationality, or political beliefs. Minority groups often face discrimination and social, economic, and political disadvantages as a result of their minority status.