Your client's father has died intestate. Therefore, the properties do not delve upon wife and children of deceased automatically. Wife and children need to obtain succession certificate from jurisdictional civil court after filing a suit. The procedure would take about a year. They need documents like family (geneological) tree, affidavit saying that they are the only successors, death certificate of the father, poperty documents etc. They need to advertise in a local newspaper about the succession and invite objections if any. After proceedings, the court would grant succession certificate upon which they need to pay a court of about 7.5% of the market value of the property. Succession Certificate need to be registered in the sub-registrar's office and registration fee is 1% of the property value.
After succession certificate is obtained, mother and daughters can execute reqlinquishing deed on appropriate stamp paper that need to be registered.