Is there any way to rename app name in lauchpad?
You can by using an Administrator account and renaming the apps in Finder. LaunchPad will show the changed name accordingly.

There also is this app, which seems to make renaming items and other operations in LaunchPad possible. Unfortunately, it seems to be discontinued, so try it at your own risk.

Finally, if you are comfortable with SQLite databases and SQL, you could manually make the necessary changes in the LaunchPad database. I'd advise you to first back up your database before you start tinkering with it. You can use the built-in sqlite3 command-line client to manipulate this database. You'll want to find the appropriate records in the apps table, and update their title field.