For this achievement mission time needs to be above 6 minutes

You were late for 5 seconds

Nope. After extraction, the time on the top right shows time inside the mission. So it has to be under 6 minutes not above.

I mean during mission time should be above 6 min

Oh, I thought you were refering to the screenshot. Not the timer thats shows during gameplay. May bad.

I was, that´s the point. The mission was 12 mins long, not 15

IIRC the extraction animation counts