Does cold approaching really work?

Those who actually approached randomly how did it go, how do you read the room whether the other person is interested or not? People who lived in ncr or in pune/mumbai/blr, where do you think it's easier to approach randomly? I don't get the chance to naturally interact so wanted to know from guys who created chances for themselves.

Also, what you talk about, how you initiate convos? How do you show to someone that you are interested in them rather than just normal hi hello talks? Any insights or how it went for you please share.