What tense is where do you live?

"Where do you live?" is present tense. The person asking the question wants to know where someone lives now.

If the person asking the question wanted to know where someone used to live, some time in the past, the sentence would be, "Where did you live?"

If the person asking the question wanted to know where someone was going to live, some time in the future, the sentence would be, "Where will you live?"