Neither Veda nor astrology subscribes to the concept of fatalism.
The chief concept of Veda is yajna - action with a goal. If everything is predestined then where is the scope for a goal and need of action to achieve it. It will simply come and fall on your lap.
Astrology prescribes choosing an auspcious muhurta for performing important events. It says that what arises out of the event - good or bad depends on the auspiciousness of the time of performance.
If everything is predetermined and future events can not be influenced then where is the scope for choosing an auspicious muhurta ?