Answer
(Fatwa: 939/745=L/1430)
In the abovementioned case, after paying all due rights preceding inheritance, the entire wealth and property of your father will be divided into 96 shares, out of which 12 share will go to his widow (your mother), 14 shares to each of his sons (you three brothers and one step brother) while each daughter (your real or step sisters) will receive 7 shares.
Wife: 12
All 4 sons: 56
All 4 daughters: 28
Your step brother who took one beegha land and half of the house, it was wrong. He owns only the portion he inherited. The selling did not take place in the portion which he sold. He should return the amount of the extra land and house to you, so that the land and house are distributed among the heirs.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband