1. First step is the POA is to be prepared indicating Husband and Wife, together called as Principal appointing wife's sister as the Attorney/Agent.
2. After the signatures of husband and wife on the POA, it has to be notarized in USA or the POA has to be got countersigned by an official of the Indian Consulate.
3. Then the POA has to be sent to wife's sister, who is in Bangalore for her to arrange for adjudication in the jurisdictional District Registrar's Office.
4. The adjudication charges for the Principal (Husband) appointing a non-blood relative (sister-in-law) through POA, i.e., will be 5% of the value of share in the property he is holding and from wife to her own sister, the adjudication charges will be nominal.
5. After the adjudication is completed, the POA has to be produced in the jurisdictional Sub Registrar's Office by wife's sister for registration of the Sale Deed ( after the sale deed is prepared ) and put her signature, on behalf of her brother-in-law and sister.
6. If an offer is made, I am ready to lend my professional help.