Depends on which character you're playing against. The matchups between Ragna and zoning characters are different for each zoning character, although they are not radically different from each other.
The general strategy is to never be hasty, since haste becomes waste ([/cheesy] haha), since they can simply punish you for some good damage if you make a slip-up. You'll want to bait certain moves for each character, punish accordingly, and once you're in you want to maintain that close distance.
However, this is just an opinion about how to approach a zoner matchup. Since matchups are debatable beyond knowledge, it's a good idea to take my ideas with a grain of salt.