My grand fathers WILL - Disparity or deceived

[vipra]

Dear sir, please share your knowledge’s. We are hindu religion family from south india. Our’s is a big family. My grand father has passed two years back, he has made an “WILL” for his 5 sons and he registered it 10 years back. My grand father’s “WILL” deed is not made in parity (i.e) three of his son is getting very big share while other two son’s are getting only a small portion of his property. My father is getting only a trivial portion of my grand father property. My father was the back bone for my grand father’s growth in all terms, my father is second son for my grand father.

My grand father was having 3 shops and my father worked in those 3 shops for almost 20 years, with out getting an single penny, so that my grand father could able to buy properties. My father was not educated, but all younger brother’s (3) of my father are well educated.

My father asked his younger brother’s (3 brother’s) that they should not try to execute the “WILL” made by my grand father (passed) and all 5 sons should get the equal share. But my father’s younger brothers are not accepting to make an equal share, they are claiming partition should take place as per the “WILL”.

Please advice is there is any way to cancel the “WILL” made by my grand father which is already registered.

How my grand father can do disparity between his 5 sons, whether this is acceptable as per any law. Ist not all kids are same for their parents

Please advice, I wanted to support my father to get his right’s in his share.

Even though my father contributed a lot for my grand father’s growth, we are asking only equal shares. Whether my father’s contribution (20 years) will be counted in front of law, since we don’t have any written proof to claim that my father was behind the success of my grandfather.

Additional Info:

1) The WILL is made by my grandfather and witnessed by two of his friends. All are expired (passed). So the WILL is still valid, if we question the geniune of the WILL.

2) In one campus my grand father constructed 8 house. He divided in such a way. 3 of his kids will get 2 big house each and 2 of his kids will get 1 small house each. My father is getting only 1 small house as per WILL. In the same campus,there are also some vacant land, which is not counted in the WILL. So i can say the WILL is not an appropriate one to follow

3) I suspect My father's younger brother would have deceived my grand father in making the WILL and register it.

Dear experts, please advice what should i do, to get my father's rights. He has given free service for 20 years without getting a single penny for his family. Please help