Dear Sir,

Yes, you will get equal share in your grand father;s property.  It is better to to file partition suit  in Civil court and get your share.

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

See if there is no will of grand father and grand mother and father is also no more then grand children have rights over the share of there father, you can apply for the partition of property seeking your share from the property.

You can file a police complaint and suit seeking father document and share in his movable and immovable property , children's married or unmarried have equal right over father's property.

it is self acquired property of grand parents 

2) on their demise the property would devolve on their sons and daughters equally 

3) on your father demise you would inherit father share along with your siblings 

issue legal notice  to  your aunts to furnish details of father bank accounts , investments made 

contact a local lawyer 

On father intestate date, his properties will inherit in his children. Divorce dose not impact inheritance right of children whether married or not.

Father inherited property from his parents and now his share will inherit in you. You are entitle to demand and take possession of everything belongs to father.

Have to suit in court to recover everything. File FIR agasint sisters for misappropriating fund.

She will not have any right if you are alive and doesn't want her to have a share. Whereas she can demand alimony from you in any manner as per the provisions of law

1. You as the Son, can file Civil Court suit, for restraining orders on Sisters to stop using Father's money /property. She will be forced to produce all the documents in court, wherein you will get a copy for further action.

If the property is ancestral property then, as per the Hindu Succession Act  he cannot transfer the property without your consent . If it is self acquired then as per his/her wish they can give property to anyone in their life time. 

If grand parents died intestate then you can claim your father share through filing partition suit before jurisdictional civil court.

Issue a legal notice through an advocate to your aunt and seek property details and others documents. 

Issue a legal notice through an advocate to your aunt and seek property details and others documents. 

If the property was on your grandfather's name  and he is no more then his property shall devolve on all his legal heirs including the pre-deceased son or daughter, provided he is reported to have died  without any Will or without any arrangement  towards this property.

Since your father is also reported to have died then his own legal heirs are entitled for their legitimate share in that property.

You can file a partition suit claiming your father's share along with your siblings

You can contact any advocate in the loan and claim the issues as per law or through the intervention of elders 

Dear sir

For your second question, you can file application under provisions of RTI .

In respect of First issue , if there was no settlement about your maintenance etc at the time of divorce between your father and mother then you are entitled for the share of your deceased father from the property of your grand parents . 

1. As legal heirs of your father your mother and siblings are entitled to get share of your father from property of your grand parents.

2. You can file partition suit for equal distribution of assets of grandparents as per Hindu succession act.