Can anybody please tell me what may be the technical issues regarding this photo ?

My guess is blown highlights and glare from the flash, harsh lighting, lack of depth of field, and noise.

For the lighting problems, try using umbrellas with multiple flashes to soften the light.

Use a smaller aperture to get more depth of field, so more of the grapes are in focus.

The noise isn't too bad, light noise removal and sharpening would help.

Finally, the composition could be better and the grapes could be displayed better. In the plastic the way they are now, I doubt there is much commercial use for the photos. Many such containers of grapes stacked in a market would be better. Or, display the grapes in a way to make them appealing to the viewer. The way they are now, there is nothing appealing about them. Search Adobe Stock for "green grapes" and compare your photo to what has already been accepted and you should see what I mean.