2006 Nissan/Datsun Maxima 3.5L SFI DOHC 6cyl vin B.
It has a chain. Do you have an owners manual? I don't see a recommended maintenance for the timing chain but I do see one for the timing belt for a replacement at 60,000 miles
Let me see if I can locate an owners manual.
I searched through the entire Maintenance Guide here and found no reference to maintenance for the timing chain all the way up to 120,000 miles.