Minor property

The mother can sell her share of the property.  If she wants to sell the minor's share, it needs permission from the Court concerned.

Whether any guardian is appointed for the minor ? If so, the guardian otherwise District Judge shall decide selling minor's share.

Yes,mother is free to sell her 2/3 share but for minor's share mother has to obtain the permission of District Judge having jurisdiction. District Judge will not grant permission until mother does not satisfy the court that minor's property is to be sold for his welfare and in interest.

The legal position is that the sale of the minor's property, without the permission of the Court, is voidable at the option of the minor as provided under Section 8 of the The Hindu Minority and Guardianship Act, 1956:

Section 8.   Powers of natural guardian.

(1) The natural guardian of a Hindu minor has power, subject to the provisions of this section, to do all acts which are necessary or reasonable and proper for the benefit of the minor or for the realization, protection or benefit of the minor's estate; but the guardian can in no case bind the minor by a personal covenant.

(2) The natural guardian shall not, without the previous permission of the court,--

(a) mortgage or charge, or transfer by sale, gift, exchange or otherwise, any part of the immovable property of the minor; or

(b) lease any part of such property for a term exceeding five years or for a term extending more than one year beyond the date on which the minor will attain majority.

(3) Any disposal of immovable property by a natural guardian, in contravention of sub-section (1) or sub-section (2), is voidable at the instance of the minor or any person claiming under him.

(4) No court shall grant permission to the natural guardian to do any of the acts mentioned in subsection (2) except in case of necessity or for an evident advantage to the minor.