The head of a Gram Panchayat in Bihar is known as the Mukhiya.
A Gram Panchayat is a village council in India. It is the lowest level of government in India and is responsible for local development and administration. The head of a Gram Panchayat is elected by the people of the village. The Mukhiya is responsible for the day-to-day running of the village and for implementing the decisions of the Gram Panchayat.
The other options are incorrect. A Sarpanch is the head of a Gram Panchayat in Rajasthan, Madhya Pradesh, Chhattisgarh, Uttarakhand, Himachal Pradesh, Haryana, Punjab, Jammu and Kashmir, and Uttar Pradesh. A Pradhan is the head of a Gram Panchayat in Andhra Pradesh, Telangana, Karnataka, Kerala, Tamil Nadu, Puducherry, and Andaman and Nicobar Islands. A Mayor is the head of a municipal corporation in India.