Hello Saurab_,
Thank you for using Apple Support Communities! I understand that you have some concerns with the quality of photos taken from your iPhone XS Max.
Let's start by confirming your iPhone has been updated to the latest iOS, as iOS 12.1 introduced some improvements for Camera preview and photos:
Update your iPhone, iPad, or iPod touch - Apple Support
Here's more information about improvements and fixes that iOS 12 updates included:
About iOS 12 Updates - Apple Support
If the behavior persists, some additional information that would be helpful to know is: does this occur in different lighting conditions? Are you using the built-in Camera app or a third-party app? Is it happening with different levels of zoom?
Cheers!