Sorry, I missed the post notification @VishwasGagrani.
So, the tileGrid rect affects the position and size of the RectangleTexture in the Image, kinda pointless for the issue u are having.
If you wanna avoid editing separately each resolution xml coordinates, adding some offsets, you have 2 options:
1 - Use another (more specifc) software to create the spritesheets like TexturePacker or Shoebox (I use myself the later).
2 - Create a Texture from a Texture... this way you can re-define the region without messing with the xml, or even taking care of different resolutions.
// assuming you use AssetsManager or created a TextureAtlas...
var offset:int = 1;// crop offset from the original texture, to avoid black lines on tileGrid.
var originalRoadTx:Texture = assets.getTexture('roadTex');
var fixedRoadTx:Texture = Texture.fromTexture(
new Rectangle( offset, offset, originalRoadTx.width -offset * 2, originalRoadTx.height - offset*2));
Mind that ::fixedRoadTx should use scale=1 (last parameter of fromTexture()), it's just a reference to the original spritesheet Texture in memory, so no memory penalties.
Just be sure save ::fixedRoadTx in a variable to use it for the tileGrid.
If you are using AssetsManager, you can store it there for later retrieval:
assetsManager.addAsset('fixedRoadTx', fixedRoadTx );
Hope it helps you.