law: Indian Christian Marriage Act,1872 
  7. Marriage Registrar
  The State Government
  
  may appoint one or more Christians, either by name or as holding any office for
  
  the time being, to be the Marriage Registrar or Marriage Registrars for any
  
  district subject to its administration.
  Senior Marriage Registrars
  Where there are more
  
  Marriage Registrars than one in any district, the State Government shall
  
  appoint one of them to be the Senior Marriage Registrar.
  Magistrate when to be Marriage Registrar
  When there is only one
  
  Marriage Registrar in a district, and such Registrar is absent from such
  
  district, or ill, or when his office is temporarily vacant, the Magistrate of
  
  the district shall act as, and be, Marriage Registrar thereof during such
  
  absence, illness, or temporary vacancy.