Originally Posted by JAIF

1)
6) The current flashback chapters show Byakuya as a child, about 16 years old maybe? And these take place over 100 years before the main storyline begins, so Byakuya is about 120 years old, probably. Renji and Rukia are of the same age. Rukia claims in the first chapter to have lived about 10 times as long as Ichigo, who is 15 years old when the series start, which would make her 150 years old, which is impossible because she's younger than Byakuya, so we can only assume she was 'bragging'. She's about 60-70 years old, if you ask me.

Hope this helps.