I am trying to make a cut template in photoshop. So I have to draw a rectangle and mark a center point on that shape (Cross or small circle). Which is the accurate way to do that. I emphasized accurate because its cut template.
You can use Photoshop alignment tools. Create a circle in separate layer that you want to place in center.
Move the circle manually in approximate center of the rectangle (if your rectangle contains multiple paths/shapes, group them all). Then you select your rectangle and circle layers, and click align horizontal and align vertical button on this toolbar:
Something like this. You can use symbol like X and later guides for more visual accuracy of center.
(Make sure there is no any other object outside your rectangle boundary, otherwise you likely won't get intended result).
A mathematical solution would be to draw two diagonals and the intersection would be the center.