The correct option is (2) "We always have to wait." This option is grammatically correct and conveys the intended meaning that waiting for the bus is a regular occurrence. The other options either have incorrect word order or don't convey the same meaning.

"Always we have to wait" has an unusual word order. While it's not entirely incorrect, it's less common in English to start a sentence with "always" in this context.

"We had always to wait" uses the past tense ("had"), which is not appropriate in this sentence. The sentence is about a current or habitual action, so the past tense is not suitable.

"We have to wait always" has the correct words but an awkward word order. In English, it's more common to place "always" before the verb or after the subject, as seen in option (2).