As per Hindu Law, properties are categorized into ancestral property and self-acquired property. Any property inherited from generations i.e., father, grandfather, etc. is called as ancestral property. All family members have right to a share in such a property. As per your query:
1. Your friend's father had acquired property from his father i.e. property is ancestral property. Hence, your friends, his sisters as well as his mother are having rights and share in property.
2. Your friend's father died in 1999 hence he need death certificates of grandfather and father.
3. As His father already died without preparing a Will. He has to obtain a succession certificate. This certificate is issued to legal heirs of a deceased. To get a succession certificate, he has to approach the District Judge of his jurisdiction to file a petition. Petition must contain the following details like time of death of his father, details of property, details of all family members, the rights of the petitioner and Absence of any impediment to the grant of certificate etc.
4. Now he has to make a family settlement deed and clearly mentioned all details including his sisters and mother and get this document registered in Sub-registrar Office. Now the property will be registered and mutated in his mother name in all government records.
5. He can get a draft prepared himself and then registered it in Sub-registrar Office or can take help of a lawyer. For this a nominal fee will have to be paid in registrar office.
6. He has to take formal consent from sisters also.
7. After completing all this process the property will be registered in his mother's name and then she can transfer this property to him or any other person to whom she wants.