You'll get 6*s when you're not looking for 6*s. Last week I tried pulling for Christmas Maple with 50 gems but I got Black Baccara instead. Am I happy? Not really, I wanted my Christmas Maple
It's okay anyways since in DMM you can get 50 gems in 2 weeks because DMM loves giving away free stuff. The chances in DMM aren't really higher, you just get more chances to roll since you get more Flower Gems.
Also if you have enough TP I would advise you to do the timed re-issues asap. There are the permanent re-issues and the temporary re-issues which only last for 2 weeks. If you want to collect as much 5*s quickly so you can eventually start doing whaleship missions you need to prioritise the temporary re-issues. Whaleship missions require 8 teams.