Since there's no wills, the disposition of property is governed by Texas' laws of intestacy. I am going to assume there is no surviving spouse (i.e. your dad's wife, a.k.a. your mom or stepmom) to complicate things.
When your grandparents died, their house went to their children equally - your father and, I guess, your uncles. When your father died, his share passed to you and your brother. However, the house remains titled in the grandparents name, so you have what is called a "beneficial interest" - you're not the legal owner, but you're entitled to the share nonetheless.
Since you're not the legal owners, the property can be sold without your permission. You don't need to do anything. However, as beneficial owners of a share of the house, you are entitled to that share of the proceeds.