The DefaultMutableTreeNode i.e. the "node" represents the data. What you see on the screen, will be the renderer.
Once you identified your node, you will have to figure out the corresponding renderer and then get it's bounds.
@Manesh, please tell how to figure out corresponding renderer for my current node.
My node is DefaultMutableTreeNode and it has no method to get either its renderer or its bounds.
DefaultTreeCellRenderer has method getBounds but this method does not anyhow refer to certain node.