law: Citizenship Act, 1955 
  4. Citizenship by descent 
  
  (1) A person born outside India,- 
  (a) on or after the 26th January, 1950, but
  
  before the commencement of the Citizenship (Amendment) Act, 1992, shall be a
  
  citizen of India by descent if his father is a citizen of India at the time of
  
  his birth; or
  (b) on after such commencement, shall be a
  
  citizen of India by descent if either of his parents is a citizen of India at
  
  the time of his birth:]
  PROVIDED  that if the father of such a person 3[referred
  
  to clause (a)] was a citizen of India by descent only, that person shall not be
  
  a citizen of India by virtue of this section unless- 
  (a) his birth is registered at an Indian consulate within one
  
  year of its occurrence or the commencement of this Act, whichever is later, or,
  
  with the permission of the Central Government, after the expiry of the said
  
  period; or
  (b) his father is, at the time of his birth, in service under a
  
  Government in India:
   3  [PROVIDED FURTHER that if either of the parents of
  
  such a person referred to in clause (b) was a citizen of India by descent only,
  
  that person shall not be a citizen of India by virtue of this section, unless- 
  (a) his birth is registered at an Indian consulate within one
  
  year of its occurrence or the commencement of the Citizenship (Amendment) Act,
  
  1992, whichever is later, or with the permission of the Central Government,
  
  after the expiry of the said period; or
  (b) either of his parents is, at the time of his birth, in
  
  service under a Government in India.
  (2) If the Central Government so directs, a birth shall be
  
  deemed for the purposes of this section to have been registered with its
  
  permission, notwithstanding that its permission was not obtained before the
  
  registration.
  (3) For the purposes of the proviso to sub-section (1), 4[any
  
  person] born outside undivided India who was, or was deemed to be, a citizen of
  
  India at the commencement of the Constitution shall be deemed to be a citizen
  
  of India by descent only.