Whether you can get an immigrant visa after the consulate or embassy denied your non-immigrant visa application will depend on certain things.
If the consulate or embassy denied multiple visa applications of yours, you should talk to an attorney. The attorney will ask you relevant questions to decide how to act in light of the denials you have received. Your attorney will likely work to present a very strong case for your immigrant visa application.
Why? Because it may appear to the consular officer that you are fixated on getting into the US by hook or crook. One way to possibly subdue this line of thought is to–when your relative files the immigrant petition filed (i.e., at the start of the consular processing case)–submit very strong evidence of your qualifications.
Most important, you should remember that whatever the reason for the past denial was, you should make your lawyer aware of it. Your lawyer must know the reason in order to evaluate many things (including whether a waiver of inadmissibility will be needed).
Work with an immigration lawyer to develop a strategy to defeat all potential problems.