Not sure I understand your 60 day point.
The FDA has 60 days to accept the filing but I do not believe that means approval of the NDA at that point.
Approval will take up to 1 year.
The issuance of a CRL means that administratively ,the application was lacking in some fundamental way.
Pokey - Accepting the NDA does not mean approval. Unless the company informs investors that the NDA was not accepted, you can assume after 60 days - it was accepted. It's like if you had a really really really big homework assignment and before checking the details the teacher checked that you at least had the basic material included. Ok, now, this CRL thing - Complete Response Letter - a CRL is basically a rejection - the letter outlines the deficiencies and the company will need to follow up with the FDA. The CRL can come any time after the 60 day period. A CRL would be really bad.