can I get shares from a brothers restaurant business?

It's not clear whether your father gave everything to your brother, or just left it to him in his will.  If your father gave the business to your brother when he was in fear of dying, your father's gift to your brother could be considered what is known as a gift causa mortis, that is a conditional gift given in contemplation of imminent death.  Such a gift is revocable by the donee as long as he lives.  Thus,  your father may be able to revoke the gift and, upon return of the gift to him, regift it, or leave it in his will, to whomever he wishes.  However, only your father has this right - if he doesn't want to revoke the gift, he doesn't have to. Nor would you have any direct rights if your father dies.  If he doesn't wish to leave you anything in his will, he doesn't have to (unless he entered into a contract that he will - married couples sometimes enter into contract that they will leave each other all their assets when they die, in exchange for the one who dies last leaving everything to the children).  However, his surviving wife would have the right, even if she was left out of your father's will, to a share of his estate (I believe 1/3), which would include not only the value of assets passing under the will, but also a share of any gifts causa mortis, life insurance proceeds, and other types of assets.