Complex sentence: When he arrives at Jack's house, Tom is greeted by a man who appears about 15 years older, who claims to be Jack's Older brother, offers to let him come in and wait for Jack.
Split into simpler sentences: When he arrives at Jack's house, Tom is greeted by a man who appears about 15 years older, who claims to be Jack's older brother. He offers to let him come in and wait for Jack.