On grand father demise intestate property would devolve on your father , his siblings equally

2) I presume grand mother predeceased grand father 

3) you and your siblings have no share in property during your father lifetime 

Nephew cannot claim from property of grand father it is self acquired property and In there life nephew or anyone has no right to it also after there demise same shall be distributed as per succession act.

In case of demise of grand father his legal heirs has right over same not the nephew here as the property shall be distributed as per succession act it's not ancestral property. Your father and his siblings and grand mother shall has right on it.

It is self acquired property of your grandfather 

2) on his demise intestate it would devolve on your father and his siblings 

3) inherited property is not ancestral property as far as your father is concerned 

4) he can execute will bequeathing property to whom so ever he pleases 

5) he can also gift the property 

6) you have no share in property during father lifetime 

Now property has acqreuid ancestral status. Brother son also have share in your father`s 1/3rd share and rest 1/3rd + 1/3rd is inherited to sisters of father. And on sisters death, their share will inherit to their children/nephew. BUT IS SITUATION IN Mitakshara law school.

In Bengal, Dayabhaga law school prevails. So on grand father death, his property inherited in his 3 children equally i.e. 1/3rd share each.

And only daughter death, her share will inherit in your father and her child/nephew.

If it's an ancestral property and was received by your father and uncle as ancestral then he can claim. But if it's in the pool of self acquired policy then he can't claim. 

Great grand child  can claim property of great grand father provided it remains undivided. 

As per Hindu succession act, check the schedule class I and II list. The property will get distributed accordingly. 

You need to apply for partition accordingly and get property distributed.

1. Not only your nephew, all the legal heirs of your deceased grandfather or their legal heirs can claim their shares of the said property of your deceased grandfather and can file partition suit.

2. Your nephew can claim his share by filing a partition suit against you which will be heard by the Court.

 If the title of your grandfather's property has not yet been interrupted by executing any deed f conveyance or will or court order, it will be considered as an ancestral property to the 4 generation heirs for which your nephew also can claim his share of the ancestral prperty despite the fact that his father is still alive.

Dear Sir,

After the death of your  grand father it naturally devolves on the following formula

Section 8 in The Hindu Succession Act, 1956

1. General rules of succession in the case of males.—The property of a male Hindu dying intestate shall devolve according to the provisions of this Chapter—

(a) firstly, upon the heirs, being the relatives specified in class I of the Schedule;

(b) secondly, if there is no heir of class I, then upon the heirs, being the relatives specified in class II of the Schedule;

(c) thirdly, if there is no heir of any of the two classes, then upon the agnates of the deceased; and

(d) lastly, if there is no agnate, then upon the cognates of the deceased.

Hindu Succession Act, 1956 [Section 8]

HEIRS IN CLASS I AND CLASS II

CLASS I

Son; daughter; widow; mother; son of a pre-deceased son; daughter of a pre-deceased son; son of a pre-deceased daughter; daughter of a pre-deceased daughter; widow of a pre-deceased son; son of a pre-deceased son of a pre-deceased son; daughter of a pre-deceased son of a pre-deceased son; widow of a pre-deceased son of a pre-deceased son.

CLASS II

1. Father.
2. (1) Son’s daughter’s son, (2) son’s daughter’s daughter, (3) brother, (4) sister.

III. (1) Daughter’s son’s son, (2) daughter’s son’s daughter, (3) daughter’s son, (4) daughter’s daughter’s daughter.

1. (1) Brother’s son, (2) sister’s son, (3) brother’s daughter, (4) sister’s daughter.
2. Father’s father; father’s mother.

VI.. Father’s widow; brother’s widow.

VII. Father’s brother; father’s sister.

VIII. Mother’s father; mother’s mother.

1. Mother’s brother; mother’s sister.

Explanation : In this Schedule, references to a brother or sister do not include references to a brother or sister by uterine blood

A grandson’s rights on his grandfather’s property depends on the nature of the property. Whether the property is an ancestral property or it is a Self – acquired property.

If the Grand Father 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 the Grand Father.

Grand fathers next legal heirs class1 are Son's Daughter's .

Grand sons cannot claim share. 

If the property belongs to your grandfather then he becomes the absolute owner of the property and nobody can claim any share in the property as a right at least not during his lifetime.

If your grandfather is not living then upon his intestate death, his property shall devolve on his own legal heirs consisting his wife and children and not beyond that especially if all his children are alive,.

Therefore your nephew nor you nor your father can claim any share in your grandfather's property at least not during his lifetime.

Your grandmother might have died, but your grandfather?,

Since this is not ancestral property in the hands of anyone down the lineage, your father and his siblings can share the property among themselves and become absolute owners of their respective share in the property.

There are no ancestral rights to anyone down the lineage in this property.

1. During the lifetime of parents their children do not have a share in their self acquired/separate property. Hence, your nephew does not have any share in the property during the lifetime of his father.

2. Property has to remain undivided for four generations to attain the character of ancestral property. Then also it has to be seen whether it is ancestral in the hands of fourth lineal ascendant as on the date on which the character of ancestral property is attained.

1. Yes your nephew can claim share from his ancestral properties.

2. He can file suit for partition of property through his guardian or next friend.

The property belings to your parents and their grandchild. A partition suit has to be filed.

If you want to partition the property then file a suit accordingly. Yes grandchildren are heirs and therefore their share cannot be denied to them.