In case you're getting confused between Capital Gains Tax (CGT) and Inheritance Tax (IHT) . . .
There is no tax to be paid on the profit made from selling a house as long as it was the person's sole (or main) residence. IHT only applies to profits on second homes, buy-to-let properties and similar.
As has been indicated, if your father dies within 7 years of gifting money (over certain specified thresholds) to you, your brother or anyone else, when his estate is totalled up for the purposes of assessing any IHT to be paid upon it, those gifts (or part of them, depending upon how long had passed since the gifts were made) will be included in the calculation. That doesn't automatically mean that there will be any IHT to pay though. IHT only cuts in on that part of an estate beyond a threshold of £325,000. (If your father's wife predeceased him, leaving him all of her estate, then the first £650,000 of his estate will be free of IHT).