I'd start by looking at the WildFly's log. The common pitfall is that something else is already listening port 8080 so WildFly can't start correctly.
I actually checked 8080 port, nothing's running as such.
Also tried installing jBOSS manually, dint work.
One more strange thing that i came across is, when i uninstalled jdk8 and installed jdk7 (as suggested in one of the forum), i could host and run jBOSS at 8080. Now i see it listening at localhost 8080. But not able to start JBPM console.
Show us the WildFly's log here.
Even the log folder is also not created. If i'm not wrong the log location shall be "..\jbpm-6.3.0.Final-installer-full\jbpm-installer\wildfly-8.1.0.Final\standalone\log"
Yes, log location seems right. Try to run ant with debugging and verbose options. And check logging configuration at WildFly's config file.