I have to resize my image to small level for a game Textures. What happens is that when i press ctr+t the re scaling gizmos appear , i reduce size my image and it looks fine, but when as i press enter its pixel distorts..... Same when i upscale its looks fine in gizmos , but as i press enter the pixels distorts again.

What is the initial and rescaled size of your image?
Also, which filter are you using (as set in the Tool Options docker)?
Can you post a screenshot of the image during scaling and after scaling.

What's probably happening is that you're seeing an on-screen image which is larger and has more resolution that the actual image and this is being scaled down and looks quite good. When this is converted to image-size pixels then you get the pixelation distortion, which is unavoidable.

For upscaling, a different filter may improve things slightly.

Those scaling operations work very well for large images but they simply can't work well for small images. It may be better to make small images at the required size in the first place, using a pixel brush to give you total control of what's in the image.