Mohameddan law is not yet codified, it is still the Textual based Mohameddan law and the same one is following in all Indian Courts.
As per Mohameddan law Orphaned Grandchildren are not entitle for any share in their grand mother or grand fathers property they will be completely excluded by their uncle and aunts.
Under Islamic Law Orphaned Grandchildren cannot step into the shoe of deceased parent and succeed to a parent's share due to " Doctrine of Representation ".
The “Principle of Representation” is not recognised by traditional Sunni Islamic law.
Representation means a more distant relative steps into the shoes of a nearer relative (e.g. a son representing his father) and inherits in an identical manner to the individual he represents.
In Shariah only heirs alive at time of death are entitled to inherit, they cannot be represented by someone else who has died before the propositus. This means that if a man dies leaving behind a son and a grandson through a predeceased son, the grandson is totally excluded by the son. This is based on the cardinal principle that the nearer in degree to the deceased excludes the one who is more remote in the same class of heirs. Some Muslim states in recent times have modified the traditional Islamic law by introducing the principle of representation to a limited degree as they fear hardship for the orphaned children of the predeceased son or daughter.
It is also important to differentiate between substitution and representation from a Shariah point of view.
Contemporary Islamic Law
In Pakistan limited representation is allowed by Section 4 of the Muslim Family Laws Ordinance 1961. This allows the orphaned grandchild to inherit on a per stirpes basis when he would otherwise have been excluded by traditional Islamic law. This Section of the Law was modified as a result of a court case settlement in the Lahore High Court (?1974). I do not have the details at hand.
For contemporary Islamic law regarding ““Principle of Representation” in other countries it is quite a while since I read about this subject and my info. may be out of date.
Egypt, Tunisa, Syria and Morocco also allow limited representation by the orphaned grandchild. The details in which the this law operates is slightly different from country to country. In Egypt and Tunisa a limit of a maximum of one-third of the net estate is enforced. In Egypt the children of the agnatic grandson and agnatic grand-daughter h.l.s also benefit from this rule.
The other method in which the situation of the orphaned grandchild has been addressed is by way of an obligatory bequest e.g. Egypt. The Egyptian scholars have disagreed amongst themselves as to how to implement the obligatory bequest for the orphaned grandchild.
BUT INDIAN COURTS ARE STILL FOLLOWING MOHAMMEDAN LAW/MUSLIM PERSONAL LAW, and the situatin for orphaned grandchild is as above only.