Hi,
I got an employment offer subject to work permit and visa. my employer recently applied a ZAV pre approval in my behalf which i neede to submit in the embassy as additional requirement. but then after weeks, the HR told me that their ZAV request was denied. Is it possible for me to re apply (how many times) for a ZAV approval on own? If so how? Is there a chance that i can request a copy of the decision for me to know the underlying reasons why the zav application was denied?

The Vorrangprüfung (aka ZAV approval) is conducted for a specific position, you can't apply without a job offer.

The most common reasons for rejections are:
- the salary is too low
- there are enough locally available jobseekers
- the position is unskilled 

What was the position? How high was the salary?