• Purchasing property and role of children

I am purchasing a site from newly formed layout from land owner(his age is 45).

The details of property is as below.

a).GRANDMA AUNT(late) ------ By WILL----> Land Owner Father(late) -----As Ancestor\ hire-arc Property-----> To Three People got legal rights on land, 1.Land owner 2.Brother 3.His Mother.

b).Basically GRANDMA AUNT(late) and GRANDPA UNCLE(late) was not any children and wrote a WILL to Land Owner Father(late) to be as legal heir of there property.The WILL is registered.

c).Brother and Mother as already given power of authority to land owner and this is registered as well.
d).The Land was given by GOVT in 1954 to Grand parents(Aunt & Uncle) as per land reforms ACT as they belong to backward caste and to sell this land GOVT imposes a condition to land owner stating to purchase a alternative land of same measurement or higher. Accordingly land owner has purchased a land as well and furnished same documents to GOVT authorities, Layout is DC converted, approved by BMRDA, also he has sold few sites in layout already.

Now concern is land owner is having two major children and his bother is having one child major.But he is not ready to get signatures by them during registration or through PA. Land owner and his lawyer argument is " There is no requirement of authorization by children since they have no authority on this current layout land, children would be having rights on alternate property(purchased as per GOVT condn) which was purchased by them for re-sell of the current land".

Even my lawyer was okied after hearing there argument, But i am in still confusion to proceed further.Could you please suggest.