There is news claiming that the Irish folk gods, the Tuatha De Danann, were really Indian, and that their followers have similar practices to ancient Indians. Is that why the Celtic people are called the 'Bhramins of the West'?
The Irish (Gaelic) culture and Vedic culture are generally understood to have a common origin in the Proto-Indo-European culture. Gaelic and Sanskrit are both Indo-European languages. Some linguists have reconstructed Proto-Indo-European deities, from which some of the Irish and Hindu deities are believed to be derived, with varying levels of confidence.
Among these are *Dehnu- (proposed origin of Vedic goddess Dānu and Irish goddess Danu) and *Neptonos or *Hepom Nepōts (proposed origin of Vedic god Apám Nápát and Irish god Nechtain).
There are also similarities between the practices and beliefs of the Gaelic druids and the Hindu Brahmins, that may share a common origin as well. However, these are not understood to have come from India. The Proto-Indo-Europeans are generally understood to have come from an eastern European or central Asian location, their descendants having migrated to both the British Isles and the Indian subcontinent, among other locations.