Hey there rishi223,
It looks like there was another Apple ID signed in when originally setting up the device or iCloud. You'll need to follow the steps below to help with removing Activation Lock:
Remove Activation Lock on the device
Follow the onscreen steps to enter the Apple ID and password you used to set up your device or your device passcode.
Learn how to find your Apple ID or reset your Apple ID password.
Remove Activation Lock on the web if a device is offline
1. Go to www.iCloud.com/find.
2. Sign in with your Apple ID and password.
3. At the top, click All Devices.
4. Select the device that you want to remove from iCloud.
5. Click Remove from Account.
Start a support request
If you need help removing Activation Lock and have proof of purchase documentation, you can start an Activation Lock support request.
How to remove Activation Lock - Apple Support
Take care!