Hinduism cannot be classified as wholly monotheistic or wholly polytheistic. Why? Because Hinduism does not hold the identity of God to be a defining, essential belief. No of their sect, all Muslims share the conviction that God is totally singular. The ultimate oneness of God is a core Jewish doctrine for all Jews, regardless of sect. However, not all Hindu religions have the same fundamental beliefs regarding who God is. According to the Dvaita school, Vishnu is a single, monotheistic god. The pantheistic Advaita school is. Some Hindus could practice henotheism. All Hindus concur on the ontological essence of God, however they disagree on a few key ideas including samsara, karma, and dharma.
It is as incorrect to claim that all Hindus are pantheistic, all Hindus are monotheistic, or all Hindus are polytheistic than it is to claim that all Christians submit to the pope. Therefore, since the question's premise is erroneous, it may be claimed that the question itself is inaccurate.
Thank you,
Eddie