Is Hindi a major religion or ethnic group?

Hindi is neither a religion nor an ethnic group.

Hindi refers to a language that is primarily spoken in northern India, and it is one of the 22 recognized languages of India. It is also one of the official languages of the Indian government. The majority of India's population belongs to various religious groups such as Hinduism, Islam, Christianity, Sikhism, Buddhism, and Jainism, among others. Hindi is predominantly associated with the Hindu community but is not limited to a particular religion or ethnic group.