Inherited grandfather property

One of you articles mentioned If the Grandfather dies without leaving any will, then only his immediate legal heirs i.e. his wife, son(s) and daughter(s) will have right to inherit the property left behind by him. In case any son/daughter of the grandfather dies before his death, then the legal heir of the predeceased son/daughter will get the share which the predeceased son/daughter would have got. My grandfather died in 1988, he had left a wife (grandmother) and 4 daughters, one being my mother who died in early 2018 (after his death). My mother would have 1/5th beneficiary if alive. We are 3 children (of my mother). Now grandfathers property is being mutated last month onlyand ready to be sold. The succession certificate has 7 names - 1 grandmother, 3 daughters (alive), and 3 grandchildren (since my mother has passed). For each grandchild, What is our entitlement - directly 1/7 th of the property. Or we will share a part of our mother’s original entitlement- 1/5 x 1/3?