1. Do you live around here?

2. Do you live near here?
3. Do you live in here?

(Are they all grammatical? #1 is the same as #2? #3 is a little different, right?)

1 and 2 are fine, and yes, they are similar.

3 will work only if you are standing in the courtyard or entrance of a large apartment building or condo complex or housing development. Otherwise, the word "here" won't make sense.