1. If it were to be Ancestral Property, then after the intestate demise of your Grandfather in 1993, the share in the ancestral property would devolve into two parts, i.e., one equal share of 50% to your father (Grand Father's Son) and one equal notional share of 50% to your deceased Grand Father. Then this notional share of 50% of your Grandfather shall be further subdivided equally to 5 daughters (your aunties) and 1 son(your father) in the ratio of 1/6 th share each. In other words, each daughter(Your aunties) of your grand father is eligible for 8.33% share in the ancestral property and your father is entitled to total 58.33% share in the ancestral property.
2. In case of deceased legal heir, the share shall be further subdivided amongst his/her legal heirs. In the instant case, the 5 daughters of your grand father are entitled to get 8.33% share in the Ancestral Property, since their father(your grand father) died in 1993 much before the Amendment to Hindu Succession Act came into effect.
3. In respect of your father's share in the Ancestral Property, since he died in 2012 after the Amendement to Hindu Succession Act, your 4 sisters and you are entitled to equal share in the share of your father(58.33%) which shall be equally sub-divided into 11.16% in your father's share in your grand father's property.
4. Suppose we consider a different scenario and assuming that the property was your grand father's self-acquired property and in the intestate death of your grandfather, the property would devolve equally to your Grand Mother(if alive), 5 daughters and a son. In other words, each of your father's sisters, your grand mother and your father is entitled to 1/7th share in your grand father's self-acquired property. In case your grand mother not alive, then each of your father's sisters and your father is entitled to 1/6th share in your grand father's self-acquired property. In case of deceased legal heir, this 1/6th share shall be further sub-divided amongst his/her family members,i.e., spouse & children.
5. To mutate your name in the municipal records in respect of the property, either the other legal heirs have to give up their right over the property and release/relinquish their share in your favour by executing a registered Release/Relinquishment Deed or you can amicably settle their claim by entering into registered family settlement deed.
6. To engage a Builder for redevelopment of the property, the consent of all the legal heirs are a must.