wget -O /etc/yum.repos.d/jenkins.repo https://pkg.jenkins.io/redhat-stable/jenkins.repo
rpm --import https://pkg.jenkins.io/redhat-stable/jenkins.io.key

NOTE: if you've previously imported the key from Jenkins, the “rpm –import” will fail because you already have a key. Please ignore that and move on.

You will need to explicitly install a Java runtime environment, because Oracle's Java RPMs are incorrect and fail to register as providing a java dependency. Thus, adding an explicit dependency requirement on Java would force installation of the OpenJDK JVM.
With that set up, the Jenkins package can be installed with:

yum install jenkins