1)it is not ancestral property
2) father can execute gift deed for 25 acres of land in favour of his son . gift deed should be stamped and regd
3) in alternative father can bequeath property by will to his son
4)once gift deed is executed duly stamped and registered your brother would be absolute owner of 25 acres of land
5) you can file suit to set aside gift deed but it has to be proved that gift deed was executed by coercion or undue influence