Checking the status is pretty easy. You can go to this page and enter your Application number. Its on the Application form.
If it says
Application Form Number ‘XXXXXXX’ is yet to be received/ processed.
It mostly means that your application has not yet been processed. You can check if your application has reached there, by the speed post’s tracking service (not sure about registered post, can anyone confirm?.. Comment).
Make sure that you have the receipt for your Speed post. You’ll have a speed post number like SP EK123456789IN
SMS “SP EK123456789IN” (thats “SP<space>EK123456789IN”)
This will atleast tell that if its there or not.
Best of Luck, people!