i mean after they killed people looks like he was not happy. why? he did noy believe his sons were right?

Shalom, Thank you for your question. According to many commentators, and the simple reading of the text, Yaakov was indeed upset with his sons for the slaughter of the men of Shchem. The Torah records that “Yaakov said to Shimon and Levi, "You have caused me trouble, making me repugnant to those who dwell in the land, the Canaanites and the Perizites. And I am but few men; if they gather upon me and strike me, I and my house will be destroyed!” This means that Yaakov believed that his sons were at fault for what they did. Some commentators explain that not all the people of Shchem deserved to be killed. Others explain that even if the people of Shchem deserved their punishment, the way it was carried out caused Yaakov to criticize his sons. For more depth on this subject, you will enjoy learning many classical commentaries at the following link – https://alhatorah.org/Sin_and_Slaughter_of_Shekhem/1/en Blessings.