Property settlement

20years back my dad purchased a land about 1acre in city limits of 1km. Because my dad waz n abroad so he made that land on his fathers name . Aftr 15years my dad's brothers asked my dad shall we build our individual houses there, so my dad said yes. Because my dad is a kind hearted. Later on my grandfather expired and then everyone wanted their share of property. In that share of property even the land which my dad purchased even that includes because it was in my grandfathers name. Even for that my dad said uh all can have your from that .. Which will be 15cent each including my dad including road marking for each. In dat, 15 cent iz on my grandmothers name . In that My dad has kept 2 conditions as that land belongs to my dad not legally but as humanity he can keep his condition 1. The land cant be sold to the third party . If anyone wills to sell he can only sell to his brothers. 2. If any of brother agrees to purchase land of from his brother he need to ask permission from my dad and my dad should agree for that only than procedure will continue. These are two conditions, for that my uncle askd what if in future if uh are not there (generally) then what should be done so for dat my dad said you should ask my sons permission (thats me). For this they dint agree. I ask your advice . Whether that condition should be accepted or not