If I activate soul exchange, and tribute for Horus Lv. 6, can it attack that turn??

I've been looking for the answer for a while

thanks!

No you cannot attack. Remember, Soul Exchange says that you cannot even conduct your battle phase that turn. Even though Horus 6 isn't affected by the effects of spell cards, that effect has no bearing on it. It's not something that affects Horus 6 at all. It affects you and the game mechanics. Not being able to conduct your battle phase isn't something that Horus 6 can "trump." Even if he was out on your field and you used Soul Exchange to summon a different monster, you still can't conduct your battle phase that turn.