Hey yashpatil,
Welcome to Apple Support Communities.
If I understand correctly, there's an issue with the installation or download of Xcode on your MacBook Pro when using the Mac App Store. If you haven't already, try taking a look at the article linked below and running through the general Mac App Store troubleshooting tips that it provides.
Troubleshooting the Mac App Store - Apple Support
If nothing happens after clicking Buy when purchasing an app
Select the Purchases view at the top of the Mac App Store window. Look for your purchased app. If it is listed under Purchases and says Installed next to it, check your Dock or Applications folder for the app. If the app's listing under Purchases says Install next to it, click the Install button. The app will then be downloaded and installed into the Applications folder. You will not be charged again for the app.
If the app is not listed under Purchases, your previous attempt to buy was not completed and you were not charged for the app. Navigate to where you tried to purchase the app earlier and click the Buy button for the app. This will charge your account for the app. If you delete the app and wish to to reinstall it later, you can use the Purchases view to reinstall it without being charged again.
If downloading an app is interrupted
Once an Internet connection is reestablished, your purchased downloads should automatically restart. The Mac App Store may alert you that there was an issue with the download and ask if you'd like to restart the download(s). Confirming will restart all pending downloads.
The download time will vary according to the file's size and your Internet connection speed. Refer to this article about iTunes Store purchases for more information about download times for large files.
Take care.
