Hi
Difficult to give definitive answer because of lack of many details.
But I'm quite sure it is not Felipe II.
Based on the upright position of the value “II” on the right side of the shield, I guess (only a guess!!) it is a Felipe III piece either from the Granada or the Segovia mints (Sevilla has the upright “II” value between dots) from the 1611-1615 period.
About authenticity I can't tell only looking at your pictures.
Let us wait for other more expert opinions.
Regards