What does John 11:57 mean?

Officially, the religious leaders of Jerusalem lack the political power to put Jesus to death (John 18:31). Roman rule typically meant allowing locals to govern themselves, under the guidance of an Empire-installed governor and other politicians. Men like Pilate and Herod could enact the death penalty, but neither of these men have a good relationship with the Sanhedrin. In addition, Jesus has amassed enough followers that any direct attack would be met with a riot (Mark 12:12; Matthew 21:46). For those reasons, it's unlikely that the Council has publicly stated their intention to have Jesus killed.

Instead, they put out the ancient equivalent of an all-points bulletin, asking to know where Jesus is. This isn't a general location, but a specific one. What they mean is for someone to tell them where Jesus is lodging, at night, if or when He comes to the city for Passover (John 11:55). The people are aware that Jesus is a wanted man, and wonder if He'll avoid the city entirely as a result (John 11:56).

What few people expect is that Jesus will not only come back to Jerusalem, but He'll do so to great fanfare and a triumphal entry (John 12:12–19). That moment is a key incident in these last days before Jesus is finally captured, crucified, and resurrected.