Below, you'll find the Pew Research Center's most up to date graphic outlining where the major U.S. religions stand on the subject of same-sex marriage. The update was released following the recent change in policy by the Presbyterian Church (USA).
Unsurprisingly, many of the largest religious denominations in the U.S. continue to prohibit same-sex marriage, including the Roman Catholic Church, the Southern Baptists and other evangelical denominations, the Church of Jesus Christ of Latter-day Saints (also known as Mormons), and the Orthodox Jewish Movement.
You'll notice that Buddhism and Hinduism have "no clear position" according to the graphic. For both of these religions, the Pew Research Center says there is no universal position on same-sex marriage. Regarding Buddhism, some interpretations hold that one of the ten "non-virtuous deeds" is “sexual misconduct," which is most often assumed to refer primarily to adultery, but some Buddhists believe this includes homosexuality. Similarly, in Hinduism, some condemn homosexuality while others point to ancient texts like the famous Kama Sutra which some believe condones homosexual behavior. For both of these major religions, there are certainly many nuances that are not covered here among many different groups of practitioners.
For more details on various religious stances on same-sex marriage, check out this fact sheet put together by the Pew Research Center.