In the context of this verse, to be "called" means to be saved. Look at verse 30:

"And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified." Theologically, those who are “called” are those who drawn to Christ through the work of the Holy Spirit in their heart and conscience. Those who are called are led to repentance (turning away from sin and towards God) and ultimately to conversion from the old sin nature to a new nature in Christ (2 Corinthians 5:17).