All previous applications have been expired without alloting ARN.
Even if you get ARN forget it and fill up application again.
For those who are getting Adhar mismatch error:
DO NOT give you aadhar number , because unless and until you correct your name spelling on adhar you cant register for gst. So adhar number is option, better not to give it.
Just verify your identity based on PAN card name.
Do it, you will get ARN in just 10 mins, forget your old application.