second legal wife n her children rights on property

My father purchased the property on first wife name in 1964 from his own money and she died in december1968 leaving 5 daughte's minor.he got married to my mother in march 1969. We are 2 brothers n 2 sister's. Now we all r married except my elder brother . my farher , mother , brother r staying this house. Electricity bill is in my farhers name but water bill is in first wife name only. All the bills r paid by us. We r in settled physical possession. One of my youngest step sister died in 1985 leaving one month old son whom my eldest step sister taken with them n bought him as their son with their names only without any adoption paper signed from his father. Now My father from 6 months staying with my step sisters stating that we r not taking care of him n given request for khatha change to first wife 4 daughters stating it is first wife own acquired n purchased property showing first wife death certificate issued on 27.02.2015 after 46 years. BBMP closed the file after our objection certificate that my father his having second wife n children also stating to get the succession certificate from court. On the sale deed there is no signature or thump impression of first wife. My father signature is there for first wife. It is mentioned on the sale deed that the earlier absolute owner is selling the property on the name ..... w/o ....working In firm this post...... Now my mother is dependent on my father. Who is not giving any money for her maintenance being central government retired also not included her name in pension passbook though shown in retirement papers. She is having this house only for her leaving n been dependent for money on us only. Now we r having proofs that this property was purchased from his money only as his old passbooks n his first wife was having no earnings. Can we get succession certificate? We or my mother is having any rights in this property or this property will be devided into first wife 4 daughters n my father. Kindly explain.