I have made a anti theft alarm using PIR sensor and Arduino.
I want to keep my board outside my home and should be able to bear rain,wind,dust etc
Is there a way to make my project water and dust proof? any water proof box comes specifically for electronics circuits? or any other way?
you are not the first one that wants to use electronics outside....
Thus I guess you did not do an internet search before you asked this question.
It´s not that difficult: https://lmgtfy.app/?q=how+to+make+electronics+water+proof
Water & dustproof is something that is resistant to dust. A plastic cover you put over your furniture that repels dust is an example of something that is dustproof.
Search for sealed enclosures or waterproof electronics enclosures, etc. I guess - guess - maybe an IP54 and upwards enclosure might be appropriate, but that might be an over-the-top solution. The link is worth reading.