I have make pull request on git (with "xcodeproj/project.pbxproj" file - my fault), so can I delete this file from created Pull Request? Thanks..
You probably will merge this pull request on master, so you can checkout just this specific file again, from master, on your branch, just type:
git checkout master -- xcodeproj/project.pbxproj
git commit -m "removing a file from PR"
git push origin {YOUR BRANCH}