law: Registration Act, 1908
  49. Effect of non-registration of documents required to be
  
  registered
  No document required by section 17 32[or by any provision of the
  
  Transfer of Property Act, 1882] to be registered shall-
  (a) affect any immovable property comprised therein, or
  (b) confer any power to adopt, or
  (c) be received as evidence of any transaction affecting such property
  
  or conferring such power, unless it has been registered:
  32[PROVIDED that an unregistered document affecting
  
  immovable property and required by this Act or the Transfer of Property Act,
  
  1882, to be registered may be received as evidence of a contract in a suit for
  
  specific performance under Chapter II of the Specific Relief Act, 1877, or as
  
  evidence of part performance of a contract for the purposes of section 53A of
  
  the Transfer of Property Act, 1882, or as evidence of any collateral
  
  transaction not required to be effected by registered instrument.]