to the best of my lnowledge there is no way to get e legitamant, tedable lvl. 9 or under Zekrom because wi-fi counts the lvl 9 or under legendary as illegal.
But here are the codes of my attempts to make a tradable lvl 5 Zekrom and Reshiram. Theirs moves and stats are crappy because i made them to try to trade to all the people who ask for lvl 9 or under legendaries because that is cheap.
Zekrom, Reshiram lvl. 5 in box 1, slots 1 and 2
Caught at N's castle at lvl 50 on March 17, 2011 in dusk ball *class 1
press select to activate code, but do it before your in your pc, if you press select while in your pc you will get a blue screen
Zekrom, Reshiram lvl. 5 in box 1, slots 1 and 2
Caught at N's castle at lvl 5 on March 17, 2011 in dusk ball *class 2
press select to activate code, but do it before your in your pc, if you press select while in your pc you will get a blue screen
Not sure if it will let you trade them, but i think i managed to trade one once. this code helps make them more legitament by turning the pokemon's ID to your's. I have it for white version, don't know if it works on black as well.
mark the pokemon while depositing
Other than that you can try getting your wi-fi signal to lag by only having a strength of one or two bars, it might help skip the checking of the pokemon and let you deposit or trade it.
If anyone wants i can make other pokemon codes, i already made a bunch of codes to have uber starter pokemon gen 1-3, and the fourth gen as well, but they are for heart gold, and they are legitament.