No person shall be capable of being taken in adoption unless the following conditions are fulfilled, namely:―
         (i) he or she is a Hindu;
         (ii) he or she has not already been adopted;
         (iii) he or she has not been married, unless there is a custom or usage applicable to the parties which permits persons who are married being taken in adoption;
         (iv) he or she has not completed the age of fifteen years, unless there is a custom or usage applicable to the parties which permits persons who have completed the age of fifteen years being taken in adoption.