Adding mothers name to property card to my father's property

We sold our father's ancestral property located in Kolhapur, Maharashtra. My father passed away in July 2017. The builder gave us token amount in Feb 2017 at the time of sale deed and the final amount was due in Sept 2017, which he dishonoured the cheque. I live in Canada and when I visited india in August 201... I read the sale deed and found out that 10sq mt.. has shown less in the deed. So I suggested the correction to which the builder agreed but never did the same until the date of cheque bounced. Now when we are demanding money he said we need to add your mother's name to the property card as a rectification to the sale deed...which is 10-15 days process and can pay you with DD. My father had no will when he passed away. My question is why mother's name to be added to the father's property? And the builder is buying time as he is aware cheque bouncing legal action should be taken in 30days? Can we not avoid the property add issue and directly ask out money from the builder? Please advice.