Yes, you can use the merge option to update your mainline branch with the changes you made in the branch named "xyz." Merging is a common way to integrate changes from one branch into another.
Refer the below doc for merging the branch to mainline
Ideally rather than merging your branch(which was created out of the main branch for a reason – lets call it a feature branch then) to the main branch and bring a possibility of corrupting the main branch, it would be a good approach to merge the main line to your branch and check if the all the features are intact along with your branch!
Call it a best practice or not, it would always be good if we make all the tests in our current working branch before attempting a merge to the clean main branch.
You need to commit your xyz branch first, and then switch to the main branch through Manage Branches Lines, then merge xyz branch into the main branch through Merge Changes Here.if there is an error you need to fix, Or rollback through Revert All Changes,all the options are in the picture above.