I am not aware that Alcohol 120% can strip Playstation region schematics from inside a NTSC game. I am not sure it even needs to.
...my friend is going to US next month,so i have told him to get me a game which is sure to be NTSC and i have a PAL ps2....should i tell my friend to buy that cd for me or not?
If your PS/2 is modified (modchip), so that you actually can playback any kind of region and any kind of (backup) game, then go for it. You will probably able to play NTSC games on your PAL PS2. It all depends on the game and your modchip capabilities.