I cant login to one of the mac laptop which is encrypted. If i check the mac on jamf it shows Personal Recovery Key Validation is UNKOWN. I have created a policy on jamf to create a local admin account on that mac by following this https://www.jamf.com/jamf-nation/discussions/31953/add-a-user-account-remotely.
Is there any way to check in the mac so it creates the local admin account.
Unfortunately, it sounds like the system is at the FileVault unlock screen, which means that the full OS hasn't been loaded yet. At that screen, I don't believe things like normal check-in or policies can run, since the disk is still locked. Without the FV recovery key, or the credentials of a FV-enabled admin account, I don't think there is anything else that you can do to get access to the system without wiping the drive and reloading the OS. Hopefully someone else has an idea that I am not aware of...
Unfortunately @Cranappras is correct. When a Mac with FileVault first boots, the OS isn't loaded and there's no network stack, so actually getting the Mac to check into Jamf to run anything is impossible in that state. The internal Macintosh HD partition isn't even mounted until after you unlock it with a valid password or Recovery key.
So in essence, if you don't know a password to unlock it, or have a Recovery key, there's pretty much nothing you can do to unlock that drive to get back into it. The only other option would be if it had an Institutional Recovery key installed, but from your screenshot above, it doesn't look like it does. Sorry, but without that and without the other 2 ways, your only choice may be to wipe the drive and reload the OS.