Syncretic. In Asia this is common; one can be a Buddhist and a Shintoist, or combine Taoism, Confucianism, and Buddhism, or one can be both a Muslim and a Hindu.
In the West, this is becoming more common. The Catholic Church calls this "cafeteria spirituality" where the believer "picks and chooses" beliefs. Many people are both Christian and Buddhist, or follow New Age practices, which can blend just about everything together.
polytheism
The reigens are hindus
Rome was very tolerant of other religions. Rome was a mixture of people from all over the known ancient world.
Voodoo is a mixture of African faiths/religions/practices/folk magics and Catholicism.
90% practice a mixture of Buddhism and Taoism; other religions exist too.
The Middle colonists were a mixture of religions, including Quakers, Catholics, Lutherans, Jews, and others.
Hellenistic culture was a mixture of Greek, Egyptian, Semitic, and Persian cultures. The Hellenistic mystery religions were syncretic manifestations of this cultural mixture.
A mixture of all religions but a major one is the Church of England, which is Protestant.
The main religion is RomanCatholicism.But like everywhere else in the world, there are also a diverse mixture of other religions, such as Islam, Buddhism, Sikhism and Judaism.
The main religion practiced in Vietnam is Buddhism. Many followers of this religion practice a mixture of Mahayana Buddhism, Taoism, and Confucianism.
The Middle Colonies were primarily Anglicans and Quakers.
Christianity, Ancestor-Worship, Islam, Judaism, Hindi, Rastafarian, Animism, Buddhism. Most commonly is a mixture of traditional Ancestor-Worship and Christianity.