I have heard that Goddess Manasa lived in Bengal. Is this true or false?
I don't think Goddess Manasa(মনসা) lives in bengal! because she is a goddess.God or Goddess don't live in earth. you might know goddess Manasa has 12 major names, one of them is Vaishnavi. though Surasa is the name of kashyap muni's wife one of the dahsha putriee. Goddess Manasa is also called Surasa. such like Padmavati is the name of goddess Lakshmi, but Goddess Manasa is also called Padma or Padmavati too. Manasa devi is a form of Shakti.as mata saraswati is power of knowledge, mata Lakshmi is power of wealth, mata parvati is power of stamina or kriya shakti. same to same Mata Manasa devi is the power of will that means ishsha shakti or chinta shakti. In Adya strotram it is said that, adi parashakti lives in nether world in the form of vaishnavi.and she lives in manidweepam in the form of Surasa. so it is clear that Mata Manasa devi maybe lives in manidweepam or she lives in nether world ( patal lok). By the way, goddess Manasa is not a just bengali devi! She is also worshiped entire Indian subcontinent in many forms,,,,, such south Indian people worship her by the names Karumariamman( Not Mariamman), Nagathamman,Nagamma, Nageswari amman etc. so i think You got your answer my friend :-)