You Have Isolated Footing 2*3 M , Where Is the Direction of Main steel ? IN any direction short or Long?

it all depends on the kind of design you employ. if you design it as a2 way span as we can see the ratio of the long and short side is less than two. then you lay the main steel in both direction. but for a longer side that is just3 meters hence the bending moment is not critical.you can lay the main steel along the shorter and provide distribution bars for the long side

The direction of main steel is in both short & long direction as the ratio between long and short direction is less than2.  

In the long direction as the bending moment is greater on the long dimension