Vedanta developed within Hinduism specifically with the aim of bringing together the diverse sects of Hinduism, while recognizing that there is not only one religion, but that instead each of us can find or develop the religion that elevates his being.
The land and history of India have been propitious for religious encounters: Buddhism, Christianity and Islam have, since their origin, taken root in India, where the Sikh religion, Jainism, the Parsi religion, and others also exist. The Vedanta’s perspective on the various sects of Hinduism applies of course to all the other religions: each one is a path of truth, but none alone can fully account for the manifestations of the Infinite.
The Ramakrishna Mission has, among others, tasked itself with encouraging and participating in inter-religious dialogue. This has been so since its origin—indeed, one of the first public actions of Swami Vivekananda was to participate in the first World Parliament of Religions in Chicago in 1893.