Hi, @buvassri .s
What is the mouse brand and model? Was the mouse working on this PC before? Did anything change recently, such as a Windows update, driver update, or new device?
Please also check whether the mouse connects directly through Bluetooth or uses a small USB dongle. If it uses a dongle, make sure it is plugged in and try another USB port.
If it is Bluetooth, switch the mouse on and put it into pairing mode. Then go to Settings > Bluetooth & devices > Add device > Bluetooth.
If issue still persists, please provide more details about the issue. Thanks!