Minor grand children have no rights in the property 

2) if minors had share in property father would need court orders to sell their share in property 

Any sale of immovable property of which  minors are owners cannot be purchases without permission of district Court. Purchase of such property can be challenged by minors after attaining age of majority. The natural guardian father or mother have to seek permission from Court, open account in the name of minors and deposit the sale consideration in the account of minors. This the procedure. Obtain permission from court and only then purchase property.

Your first question gives the impression that minors are also joint owners with major members of family. It minors are not mentioned in the title deed your can purchase the property. The only precaution is that sale deed should be properly drafted safeguarding the interest of minors.

Minor children have no share in property 

their consent is not necessary for sale of property 

Hi, you must mention the names of Minors represented by their Natural Guardian in the Sale Deed. So that it is sufficient. 

2. You can't take consent of the Minor children in the Sale Deed.

Dear sir,

You need to obtain the prior permission of the court for selling off the property which is in the name of the minor.

Such sale can be challenged by the minor after attaining majority if there is any illegality or anything which hampers the interest of the minors.

Dear sir,

if Minor children are not owners of the property, they have no share over the property. But the consent of minors is necessary.

Thank you  

1. As per your narration, it appears that mother and her two sons were allotted a Site.

2.  If the Site allottees are alive, then there's no need for grandchildren's signatures on the sale deed, as it's the self acquired joint property belonging to the mother and her two children and except them no other person, including grand children have any right over the property.

3.  Moreover it's to be noted that minor children are not legally allowed to enter into contract as sellers or witnesses.

- Since it is a self acquired property of the two sons , then the married son has his right to sell his share in the property without taking the consent of his legal heirs including wife and children 

- Hence no consent needed from the minor sons of married one . 

If the allottees are alive and they are executing the registered sale deed in favor of the buyer jointly,  then there's no question of their children either minor or major to give consent or to sign the sale deed. 

The allottees are the absolute owners of the property hence their children cannot claim any share in the property either now or at a later stage. 

The children either minor or major by age don't have any rights in the property hence it is not necessary to include their names as vendors in the registered sale deed. 

For selling minor share you need permission from. Court. 

In your case, minor children have no right over the property. You can register the sale deed from the mother and two childrens