If appears very wide
Hi @RAHUL_singh1 and welcome to the Quick Community!
So from it looks like to me based on your screenshot, it seems like the bars are very wide based on the little data shown (only showing Dec 2025 and Jan 2026), as well as it looks like the visual itself is spread horizontally across the full sheet. Quick Sight has a built in function that auto adjusts the size of the visual to fit the space that you have set. So in this case, the bars are wide because I think there is not that much data shown and its trying to cover the space given that the visual is set that wide. I would recommend either adding a few more months into the visual and the visual will adjust (change bar size) to adjust for the added months. Or I would recommend making the visual smaller on your sheet.
Another you can do is add a legend to your visual and then change the size of the legend. That will reduce the size of your visual another way which will make the bars not as wide. Refer to the screenshot below on how to change the legend size.
One last idea you can try out is to change this visual to a Highchart and create a variwide chart. This is essentially the same as a bar chart, but for this visual you can set a value or field to dictate the width of the bars. Here is the link to an example (DemoCentral). Make sure to head over to the ‘Samples’ tab within the webpage and you’ll find the visual I am talking about after you scroll down a bit.
With all that said, there is unfortunately not a way to manually change the bar widths within the properties panel. I will attach the ‘feature-request’ tag to this post to help promote visibility to the Quick team.
Hope this helps!