The Manaslu Circuit Trek lies above the foothills of the Gorkha District. You will encounter people of various ethnicities like Brahmins, Chhetris in the lower regions. But as you trek to the high altitude regions, you will meet Gurung people. The Gurungs of this region are adherents of Tibetan Buddhism.
You can see the influences of Tibetan Buddhism in various places along this tr... https://missionhimalayatreks.com/trips/manaslu-circuit-trek