i dunno if this is a stupid question
 

...but can I watch ayu dvd concerts on my ps2?

It depends on what region dvds your ps2 will play. Mine will only play region 1 dvds, so i can't play ayu dvds. If yours is region 2, it shouldn't be a problem.

thats right just like biscuitgirl said! ^^

I have the Dome Tour (Zone 2) and It works like a charm on PS2 and XBOX (the two are european versions) without any chip added ...(preference goes to PS2 for the image quality ...that's strange)
For PS2 : "DVD regionX" is a disc that can play DVD from other zones. Perhaps it's only available in europe . I don't know .

how do i check wad region dvds will my ps2 play?

I think you can !! unless your PS2 was bought else where in the world with diff region code

buy a gameshark 2 get the ps2 modify.