Can I ask HR if interview will be mostly behavioral or technical and with who?

You didn't specify where you are interviewing. At BB's (and most other places for that matter) when you are invited to a first round they will ask you to first schedule times that work best for you and then respond with a set time and the person who will be calling you. You shouldn't really need to ask about behavioral/technical because it will be a combination of both and asking implies you don't necessarily know your stuff and thus aren't quite knowledgeable on whatever the role you're applying to is.

Once again it depends on the specific role you're applying to. My first round with SIG was almost purely brain teasers and probability questions. My first round at the tier 1 BB's were more behavioral and market based.

For the love of god do not ask if it's going to be behavioral or technical. You need to know both, and asking which it is makes you look childish and unprepared. The person that handles recruiting for my bank usually forwards emails like that to the interviewing bankers prior to the interview... it's not an auto-ding per se, but it reflects really poorly on the candidate.

Yea dont ask, horrible impression. Like asking your teacher whether something will be on the exam, just becuase you are too lazy to study all the material.