Niggas ain't made me if niggas they can't be.
This line comes from Dr. Dre's "The Watcher," so you must understand that rap lyrics are almost strictly slang, and often phrased oddly just so they fit the rhythm or rhyme, and may not necessarily be common usage.
That said, in this verse Dre says:
I moved out of the hood for good, you blame me?
Niggas aim mainly at niggas they can't be.
But niggas can't hit niggas they can't see.
He is lamenting the fact that young blacks in the urban neighborhoods target older, more successful blacks for violence out of frustration. They feel that they'll never be what someone like Dre has become, so they act out with guns. This is why Dre moved out of the 'hood (urban area) to a safer, suburban area. The younger boys can't shoot him if they can't see him.