Section 136(3) in The Bihar Panchayat Raj Act, 2006
(3)If a person, who is chosen as a member of Panchayat, a Mukhiya, a Sarpanch [or Panch] [Inserted vide Section 16 of Amdt. Act 10 of 2009.] is or becomes member of the Lok Sabha, Rajya Sabha, State Legislative Assembly or State Legislative Council, or is or becomes a Municipal Councillor or a Councillor of a Municipal Corporation or a Member of a Sanitary Board, or a member of a Nagar Panchayat or a member of any other Panchayat or Mukhiya, Sarpanch [or Panch] [Inserted vide Section 16 of Amdt. Act 10 of 2009.], then within fifteen days from the date of commencement of the term of office of a member of Lok Sabha, Rajya Sabha, State Legislative Assembly or State Legislative Council, or of a Councillor of Municipality or Municipal Corporation or a Member of Sanitary Board or Nagar Panchayat or a Member of other Panchayat or Mukhiya or Sarpanch [or Panch] [Inserted vide Section 16 of Amdt. Act 10 of 2009.], his seat in the Panchayat shall become vacant unless he has previously resigned his seat in the Lok Sabha, Rajya Sabha, State Legislative Assembly or State Legislative Council, Municipality or the Municipal Corporation, Sanitary Board or the Nagar Panchayat or of any such Panchayat as the case may be.