I have deleted my keystore now I have updated my apps and want to sign apk I have created another keystore and signed my application with that when I upload my app it gives me error your apk is signed with different key. Now how to resolve this issue any body help ?
Keystore is meant to prevent unauthorised updating of the app. If you don't have it (and its password), you can't update your app.
Unpublish the old app and publish a new one. It will probably require a different package name as well.
PS: Backup the keystore and your code this time.