‘Get wind of something’ means to come to know about something which others are trying to keep a secret.
Example: Jai got wind of the fact that I was taking Sarita to a movie. * My father wanted to throw a surprise party for my sister. He made sure no one got wind of it. My friends got wind of the fact that the market was going to crash.
The idiom came from animal world. Animals smell the wind to figure out which other animals are nearby. The wind carries the scent of the other animals.