Minor property

The property has to be divided into four shares and 2 sons, daughter, mother gets an equal share.

The mother's share will be further divided into 3 shares to two sons and daughter equally.

The legal heirs are entitled to the share that comes to the deceased and it should be divided within his legal heirs equally. That means the deceased's wife and son gets the son's share equally.

The deceased son's property goes to his wife and their children.  Mother is entitled and not mother's legal heirs.  Son being minor, the son's wife gets her share and her son's share as a guardian, which she can even dispose of for the necessities of the minor.

Now you can calculate the value on these proportions.