Here is the full list of all 5 NBA 2K6 achievements worth 1,000 gamerscore. It takes around 1-2 hours to unlock all of the achievements on Xbox 360.
This was achieved by getting 20 rebounds in a game with any player.
This was achieved by making 15 3-pointers in a single game.
This was achieved by scoring 140 points in a game with any team.
This was achieved by scoring 50 points in a game with any player.
You need to get a triple-double with any player from any team for this achievement.