Yes, a British royal can legally marry a Hindu.
Historically, the main restriction on royal marriages was related to Roman Catholics. The Act of Settlement 1701 prohibited anyone who was or married a Roman Catholic from succeeding to the throne. This was due to historical concerns about Catholic claimants and foreign influence.
However, the Succession to the Crown Act 2013 amended this rule. Now, a royal can marry a Roman Catholic without jeopardizing their place in the line of succession.
Therefore, there are no legal impediments preventing a British royal from marrying a person of Hindu faith (or any other faith besides Catholicism until 2013). The choice would ultimately be a personal one, potentially subject to societal and family considerations, but legally permissible.
