Can u please help me know that i am having an original apple battery installed in my iphone 11

The message you're getting is related to this support article, specific for iPhone 11 series. Please read it:--> About recalibration of battery health reporting in iOS 14.5

If you are the original owner of that device AND if you bought it using Apple Official channels (Apple shop online, physical Apple Store or authorized Apple reseller), your battery is an original/genuine part for sure (unless you had that battery replaced by a 3rd party repairer).

Regards

Giulio

Sorry no.

However, the positive note is that the device is reacting to the recalibration of the battery (keep in mind that it could take a few weeks to optimize its operation) and this, without giving you certainty, makes me think that the battery may be original.

To be sure, wait for the recalibration to finish, then you can make an appointment and have the iPhone inspected at an Apple Store or Authorized Service Provider.

Regards and best of luck.

Giulio