Property gift deed

My father executed a gift deed (Registered) in favour of my elder brother without any knowledge of myself (younger brother) & my sister. I got to know after 2 monrhs of my father death. My father was living with my elder brother when he died. I have given almost 60% of the money to built the house and paid all medical expenses of my father. Now my brother claiming right on the entire property. Gift Deed us registered and witness are my Brothers wife and one of hus friend. Can thus gift deed be challenged and what about the money i paid to built the house? Thus property has 4 floors out if which 2 are locked, i am residing in one of the floor and one is with tenant.....Can you please help me how to take this forward?

My father executed a gift deed (Registered) in favour of my elder brother without any knowledge of myself (younger brother) & my sister. I got to know after 2 monrhs of my father death. My father was living with my elder brother when he died. I have given almost 60% of the money to built the house and paid all medical expenses of my father. Now my brother claiming right on the entire property. Gift Deed us registered and witness are my Brothers wife and one of hus friend. Can thus gift deed be challenged and what about the money i paid to built the house? Thus property has 4 floors out if which 2 are locked, i am residing in one of the floor and one is with tenant.....Can you please help me how to take this forward?