I accidentally deleted a row from info.plist, is there any way to retreive it back ?
Depends on the row, maybe, but you might try creating a new project using a similar template, then finding that row in that app's Info.plist to use as an example.
Recreating that row might not be difficult...see the docs: About Information Property List Files
Be careful editing that plist - best to do if thru Xcode's UI and not as a source file in or outside of Xcode. Do not edit it outside of Xcode unless you know what you're doing, you could munge the entire file.
You might want to use this as a learning moment about the value of having a tested and reliable backup in place at all times 😉 - also, be aware that Xcode doesn't provide the same undo/undelete features as most text editors/word processors, whether you are edtiing a plist or code. Be careful and get that backup going now.
Good luck.