No, sorry you can't. You see, Braviary and Rufflet are exclusive to White 2, like Elekid and it's eveloutions, so the only way to get them is to trade from White 2.
But there are some good pokemon worth catching in Black 2 that are exclusive to it aswell, like Magmortar
Hope I helped! :D
Exclusive to White 2
Exclusive to Black 2
There are a lot more pokemon exclusive to each version, but I would say these two are the strongest (non legendary) for each version exclusive pokemon