It appears that Zoroastrianism had some influence in India. For instance, soma was a part of early Zoroastrian rituals, as it was in the Vedic religions. Zoroastrianism spread to India along with the Persian Empire and declined after that empire fell.
After ancient times, other religions would come to India, most notably Islam. The latter would become the dominant faith in the extreme western and eastern ends of the subcontinent. These areas are now known as Pakistan (PAH-kee-stahn, site of the Indus Valley civilization) and Bangladesh (BAHNG-lah-desh). Another important faith was Sikhism (SEEK-
Izuhm), which like Buddhism developed out of Hinduism. Sikhism took hold in northwestern India during the a. d. 1400s.
But during ancient times, when the arrival of those faiths still lay far in the future, the only significant religion other than the Vedic/Hindu faith and Buddhism was Jainism (JYN-izm). The founder of the Jain faith was Vardhamana Mahavira (vard-hah-MAH-nah mah-hah-VEER-ah; 599-527 B. C.). Like Buddhism, Jainism originated in the eastern part of India. In fact, there are numerous similarities between the two religions and their founders, who lived at about the same time. Like Siddartha, Mahavira was born a Kshatriya, but he left his home around the age of thirty to embark on a life of meditation and study. After twelve years, he reached a state of enlightenment, becoming known as Jina (JEE-nah), or “Conqueror.”
Though completely separate from Buddhism, the principles of Jainism are remarkably similar, involving a quest to be freed from the cycles of reincarnation. On the other hand, Jains, as believers in this faith are called, place a great emphasis on ascetic practices, which the Buddha opposed in favor of his “Middle Way.” Jainism gained far fewer converts than Hinduism or Buddhism. In modern India the religion claims only about 3.5 million believers. Nonetheless, the Jains' belief in ahimsa (ah-HEEM-sah), or nonviolence, would have a great impact on the Mahatma Gandhi, India's greatest modern leader.