maven installation setting up bash profile - maven

Question

When I do a mvn -version I get the following error
FYI:- I saw the other related posts and none of it is resolving my prob
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/maven/cli/MavenCli : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637)
at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:401)at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:254)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
at org.codehaus.plexus.classworlds.launcher.Launcher.getMainClass(Launcher.java:144)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:266)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
My bash profile is set as follows:
export JAVA_HOME=/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
export M2_HOME=/Users/ashvithavenkateshkumar/Downloads/apache-maven-3.3.9
export PATH=$PATH:$M2_HOME/bin
Can someone please see what is going wrong here.
Also I am getting the error java home not found if the path is given as JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.6.0_65.jdk/Contents/Home
but if I give as JAVA_HOME=/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home then it works fine. (The difference is if i remove the _65 and jdk in front of the version)