Hello Ajay.
The problem you are currently experiencing may be a software bug or hardware bug. Try going to Settings > Bluetooth and Devices > Mouse > Additional mouse settings > Hardware. And then next to "Device Status", it should say "This device is working properly."
If not or if it does but the mouse is still broken, that means the problem is in the hardware, and you should do one of the following:
* Get the mouse repaired
* Get a new mouse
* Download an app on your phone that turns it into a trackpad (not the best solution)
Thank me later.