Hi Abhishek,
There are several things that can cause excessive battery drain on a wireless mouse.
Interference with the wireless signal can cause the mouse to have to boost its signal strength in order to maintain communications, which will require more power from the battery. Check for any wireless devices placed close to your work area that could interfere; that may include cordless phones, WiFi routers/repeaters or other wireless devices such as a keyboard attached to the computer. Move or shut off devices one at a time and see if that helps.
Dust or dirt in the optical path of the mouse's laser can cause it to have to boost the laser output and use up batteries faster. Clean the laser lens and make sure the area you mouse on is dust free.
Also, a dark surface like black or dark blue will cause the battery to drain faster than a light colored surface, so if possible try switching out your mousepad or whatever you use the mouse on.
Of course, check the battery connections for any kind of corrosion or rust; those things will increase the resistance between the battery and the mouse and cause it to drain faster. If you find some, clean it thoroughly.
That's all that comes to mind; hopefully one of these will help. Good luck and let us know what you find!