AJ suited on button, tough decision

$3 tournament on Pokerstars.
Blinds 300/600...I have 6506. Average is 9000. Table has been playing pretty tight.
I am on the button with AJ diamonds. Everybody folds to me. The SB has 11,718 chips and has been playing tight. The BB has 5430 chips before posting the 600.

This is a good time to raise, right? I raise 1200 to 1800.

The SB folds. The BB re-raises all in for 3630 more.

The pot now contains 7530 chips. Call or fold?