Yes a gift deed can be challenged before a court as the property is an ancestral property.

You can file a suit for partition seeking partition and separate possession on the basis of oral partition among the family members including your grandfather during the lifetime of your father and ask for separate possession of your share in the property.

You can plead that you are residing in the same property for over four decades and on the basis of oral partition happened earlier, you are entitled for a legitimate share in the property and file the suit for partition.

You can also State that your grandfather created a sham or nominal gift deed only to deprive your rights hence that gift deed to be declared as null and void.

Yes it can be challenged on valid grounds of fraud wtc

You can file suit to set aside gift deed if grand father is not mentally fit or executed out of coercion or undue influence 

If there is a restraint order in a case filed under PWDV Act then such transfer will have no effect. 

- If the High Court has passed the order against him, then legally your grandfather is bound to comply the same. 

- Further, after passing the order , he cannot gift the property to your aunt to over pass the order of the court.

- Hence, you can file a declaration suit before the court to cancel the gift deed .

Dear Client,

The Maintenance and Welfare of Parents and Senior Citizens act defines "senior citizen" as any person being a citizen of India and 60 years or above. Senior citizen is eligible to get back their property given via gift deed from their children/legal heirs if they fail to provide basic necessities as mandated under the law. A senior citizen is required to apply for declaration with the court/maintenance tribunal for making the old transaction (gift deed) void. A senior citizen can even apply for recovery of property and assets from her grandchild in the event of the grandchild refuse to take care of the senior citizen or does not comply with the obligations extending to the needs of the senior citizen to lead a normal life.

1.   It is not clear as to how your grandfather can attempt to out you based on maintenance act?

2. If it was an eviction suit filed against you which has been finally rejected by the Court on specific grounds , on the same grounds your Aunt will find it difficult to evict you.

3. Unless there is a stay order and if your grandfather has a clear title of the said property, he can deal with the property in any way he feels like including gifting the same.

It is necessary to peruse gift deed to advice 

once gift deed is executed aunt is absolute owner of property 

donor can impose conditions that allow them to retain certain rights over the property, such as a life interest

 Gift Deed for conveying the title of a property can not be for 5 years. If it has been so done, then it is an invalid gift deed.

A gift  is not a time bound act  hence a gift deed valid only for 5 years  is not a valid gift and the gift deed is not legally maintainable. 

When the donor gives an immovable or movable property through a Gift Deed, it is valid forever. The validity of a Gift Deed is not affected even if the donor passes away instantly after gifting the property.

Dear Client,

When the donor gives an immovable or movable property through a Gift Deed, it is valid forever. The validity of a Gift Deed is not affected even if the donor passes away instantly after gifting the property.  

No such conditional gift deed is not valid