Dharmic traditions and philosophies have spread across the world through trade and immigration despite never proselytizing. The pluralistic orientation of Dharma makes it universal, capable of coexisting with local philosophies and practices across the globe.
No, Hindu Dharma does not have a concept of conversion, Ancient civilizations such as China, Japan and even the Greek sent their ambassadors to Hindu empires to study and understand them, some of them carried back the philosophy which then took the form of Buddhism in China, Japan or Hindu Dharma in South East Asia. Recently in the west, people are often attracted to Hindu Dharma due to its contributions to yoga or the path of Bhakti.
