Acts 15:6

And the apostles and elders came together
And also the brethren, or private members of the church, even the whole church, as appears from ( Acts 15:22 Acts 15:23 ) . Whether all the apostles were here present, is not certain; Peter, James, and John were; but who else, cannot be said: these met together

for to consider of this matter;
to hear what was to be said on both sides of the question, and then to judge what advice was proper to be given to the Gentiles.