law: Hindu Adoptions and Maintenance Act, 1956 
  11. Other conditions for a valid adoption 
  In every adoption, the following conditions must be complied
  
  with:
  (i) if the adoption is of a son, the adoptive father or mother
  
  by whom the adoption is made must not have a Hindu son, son's son or son's son
  
  (whether by legitimate blood relationship or by adoption) living at the time of
  
  adoption;
  (ii) if the adoption is of a daughter, the adoptive father or
  
  mother by whom the adoption is made must not have a Hindu daughter or son's
  
  daughter (whether by legitimate blood relationship or by adoption) living at
  
  the time of adoption;
  (iii) if the adoption is by a male and the person to be adopted
  
  is a female, the adoptive father is at least twenty-one years older than the
  
  person to be adopted;
  (iv) if the adoption is by a female and the person to be adopted
  
  is a male, the adoptive mother is at least twenty-one years older than the
  
  person to be adopted;
  (v) the same child may not be adopted simultaneously by two or
  
  more persons;
  (vi) the child to be adopted must be actually given and taken in
  
  adoption by the parents or guardian concerned or under their authority with
  
  intent to transfer the child from the family of its birth 2[or in the case of
  
  an abandoned child or child whose parentage is not known, from the place or
  
  family where it has been brought up] to the family of its adoption:
  PROVIDED  that the performance of datta homam shall not
  
  be essential to the validity of adoption.