after getting AOR is there any chance of having the application get back because of incomplete package ?
From CIC website...Hope it helps
Submission
Completion check: Once you have submitted your application, we will check to make sure:
all required application forms have been properly completed and submitted,
the application processing fee has been paid, and
all required documents from the document checklist have been submitted.
If your application is missing any of the requested documents, it will be returned to you. Failure to provide supporting documents in certain circumstances may result in the refusal of your application.
Acknowledgment of receipt: If your application is complete, it will be placed into processing. You will be sent a letter or e-mail that:
notifies you of this fact and provides you with your IRCC office file number
sets out some basic instructions for contact with the IRCC office processing your file
gives you a brief outline of future processing steps
Processing
Review for decision
Your application will undergo a detailed review by an IRCC Officer. The Officer will consider all the information and documentation you have provided, and will assess it against current selection standards.