the answer above is right.
Just want to add to one thing.
들르시오-it is sentence for writing. we dont speak with that sentence.
you can say 우리에게 들르세요 to someone who is younger and close to you somehow or familiar to you in polite way.
우리에게 들르십시요 is the way much more polite.
BUT we dont say often 들르십시요.
우리를 방문해주시면 감사하겠습니다. or 와주시면 감사하겠습니다. would be better.