To attain 6 masterballs or 6 rare candies a day, you must have 1+ rare candy or Master Ball, Pokemon Emerald and Pokemon Diamond/Pearl. In pokemon emerald, go to the Battle Tower in the Battle Frontier, give your master ball/rare candy to a pokemon and use the Pokemon Clone glitch in Emerald untill you have 7+ masterballs/rarecandies. Then migrate the 6 pokemon holding those items to Pokemon Diamond/Pearl. Repeate this untill you have as maney masterballs/rarecandies as you need in Diamond/Pearl. Make sure that you leave at least 1 masterball/rarecandy in Emerald so you can clone it as needed.

View: Pokemon Diamond Cheats - DS Cheat Codes