I want to buy a mouse n my budget is upto 500
Under Rs 500
So do you mean Rs=Indian Rupee. If so that's about $8 US.
I would believe that the general price range for a generic inexpensice mouse is about that price but anyway....
Are you looking for someone to recommend a certain brand or type for that price?
With that price range, you are going to have trouble finding anything other than inexpensive, low quality mice.
For general purpose use Logitech M105 will be handy and if you are gamer guy then u really need to pay good for a gaming mouse and pad.
Your budget is quite low but you can buy mouse of various companies like circle, iball, logitech etc which can be find in your range. But if your bugget is higher then will prefer you Razor an corsair mouse which are excellent manufacturers of mouse and other accesories.
A4TECH is best forever , i also use A4TECH ,
Logitech mouse is really very comfortable to work with as you asked for it will be under you budget. Also you can prefer for Dell mouse it will be more comfortable for scrolling than logitech.