Leveling DRG from 34 ?

So from 34+ what rotation should i be using to able to do good damage in groups (for leveling) and maybe fates ?

At that level, you don't have much of a rotation. Basically, keep Phlebotomize and Heavy Thrust up (make sure Heavy Thrust is from flank for added damage) and spam your Full Thrust combo. Use Blood for Blood and Internal Release (Pugilist cross-class) as much as you can for added damage. Also be sure to Jump whenever it is off cooldown (if you aren't at risk of being hit by an AOE during it).

Later on, you will add in your Chaos Thrust combo, balance Blood of the Dragon, and have extra jumps/buffs to weave into rotation. But at 34, it's all pretty basic.

Also, I like to use Life Surge right before Full Thrust, as it gives the most bonus damage overall. Keep in mind, Life Surge and Leg Sweep can be used for added damage, just make sure you aren't making the target immune to stun if it has AOE's or to use Life Surge early if you think you will need the heal later on.

The old rotation won't really be complete without Chaos Thrust @ lvl 50

So, up to 49 just follow these rules
1) Keep Heavy Thrust up and don't clip early
2) Keep Disembowel up on the target unless it will die in a couple GCDs (i.e. Very weak trash)
3) Keep Phlebotomize up on the target (Unless, again, it's about to die) and don't clip early
4) Use your buffs (Internal Release, Blood for Blood) and Life Surge only on Full Thrust
4) Use your Jumps and Leg Sweep

...Or just FATE grind in CCH and then Northern Than and do whatever the heck you want lol