Pls suggest alternatives available to acquire our portion of house as per will

Querist :
Anonymous
(Querist) 09 November 2011
This query is : Open
Hi
First i would like to tell you the family structure. My grand father has 6 sons & 3 daughters. My father is 2nd eldest son. My grand father has one house in delhi with 3 floors including ground.He called my dad to write his will as he had maximum trust on my dad. According to the will, house is divided between his three sons, i.e. ground floor to my dad , 1st floor 2 his 5th son & 3rd floor to 6th son. Rest sons were given shops. That will has signature of my grand father, 2 withness which is my nanaji n my dad'z frnd. This will was made 40 yrs back & after 1 yr of the will, my grand father passed away. Even after few yrs my grand mother & nanaji, who withnessed the will also passed away. But that will does not have signature of any sons & daughter of my grand father. 40 yrs back my dad had his job in lucknow. so, he shifted there and constructed his own house there. For the time being he gave his ground floor portion to this 4th no. brother to live as he has no house & no son. My dad thought, there would be no compulsary acqusition of his portion as he has no son. But his 4th n 5th no. brother joined hands together & they are not ready to leave the house. The 5th no. brother has one son & has own 2 houses. He is greedy & says that 'will' is fake. He has power & money. He feels if we are going to take any action then he will prove the will fake as it does not have signature of all sons & daughter.
As we are thinking to shift in delhi & want our house back. Please suggest me what can i do in this case. Even one witness is alive. We want to take an action as soon as possible as he is aged. Even 3 owners of the house as per the will including my dad is paying property tax since 40yrs.
pls pls suggest me, so that i can help my dad.