The biggest thing the Aryans gave the world is Hinduism, a major religion.
Hinduism developed slowly, coming together over 1,000 years during its Vedic phase. It’s still evolving. Unlike Buddhism, Christianity, or Islam, the start of Hinduism cannot be traced to one founder with one set of ideas. Its beliefs came from many sources. They include the Vedas of the Aryans and practices borrowed from pre-Aryan peoples of India.