claiming my grandfathers property

The oral wish of your grandfather will have no validity now.

Therefore the entire property has to be divided in 4 equal share (1 for you, 1 for your step brother and 1 each for your step sisters).

This will be final.

You can straight away file a suit for partition demanding your 1/4th share.  For this approach a local lawyer who is well versed in property law.

It is your mistake in not telling that the matter relates to Muslims.

You have to give details like in which year the first wife died

In which year your father died

In which year your step-mother died

Only after knowing this a broad picture can be given.

In any case, since there are lot of details which only you know, which you will not be able to discuss in this LCI, you have to get in touch with a lawyer in your area who is well versed in property law (especially muslim law) and discuss the matter with him in detail.  Thereafter, you have to take appropriate legal steps.

Hi! Thanks for the question!

Firstly, As per the Hindu Succession Act, as all the children are legitimate, your father has right over 1/4th of the total property if there is no will written by your grandfather, be it a self-acquired or an ancestral property of your grandfather.

Secondly, A verbal will has no validity if it has not been reduced to writing and duly executed during the lifetime of the deceased, thus what you grandfather said would, unfortunately, be of no use to you. Such wills are only enforceable in rarest of rare cases where it can be proved to that extent.

Lastly, Your aunts cannot decide how the property will be disposed off. You can file a partition suit and claim the part of the property that legally belongs to your father i.e 2375 sq.ft out of the total 9500 sq. ft property.

Good Luck!

The querist has clarified that all involved are muslims.

As you have disclosed that you are a Muslim, this would help you get a clarification on the matter, however, you will need to engage a proper lawyer who is an expert in Muslim Laws. 

This is the basic partition break up under Muslim Personal Laws in India - 

• SHARERS - they are entitled to a prescribed share of the inheritance. In case of a man’s property, his wife/wives are the sharers of his property. The wife is allowed to inherit a fixed share from the property of the husband which is 1/6th of the total share.
• RESIDUARIES - who do not have any prescribed share in the inherited property but they are eligible to inherit whatever is left after giving away the part of sharers. The children, both sons, and daughters are residuary in the father’s property. A daughter is allowed to take her share in the partitioned property irrespective of her marital status. They are to distribute the remaining 5/6th part of the property among themselves. The share of the son and the daughter are in the ratio of 2:1. The son is entitled to double the amount of property than the daughter.
• DISTANT KINDRED - are all those people who are related to blood to the property owner but do not fall into the category of sharer or residuary. There right is not ipso-facto present on the property, but needs to be proved.

https://lawrato.com/property-legal-advice/widows-share-in-her-husbands-property-under-muslim-law-43555

Go through the link once to get more clarification about the same. As the information provided by you is still not enough, the portions of each member cannot be ascertained. So again, an expert in Muslim law if your best course of action here. Good Luck!