I'm not a new player..already went from 1-65 as Inquisitor and Warrier..so I know how to defeat Hutt Cartel Isotope-5 Prototype Droid...but frankly, my Imperial Agent really sucks..at it..as he doesn't have enough HP to hang in there to get the job done.. his Rifle is way underpowered... less than half the energy of just 1 of my warriors dual sabers...yes I have legacy heroics..companion sacrifice etc. But he just won't stand up to droids explosive shells more than once if Kaliyo can't heal me in between...at level 55 my imp gHP is only about 24k..and I don't think they adjust the Droid HP downward ..from what the warrior faces..any suggestions???: my warrior defeated the Droid by turning on the turrets and his using his own brute force in about 70 secs...

Do you play him as Sniper or Operative?

Both need an relative exact rotation, for Energy and Damage.

The Operative is beside his Gun not an ranged Fighter but an melee one.

 

I would strongly recommend to look a guide up for example:

 

http://dulfy.net/2015/11/27/swtor-4-0-marksmanship-sniper-pve-guide-by-thrax/

Firstly, don't stand in red circles. They will kill you. They are designed to kill you, regardless of class.

 

It would also be beneficial to know what Advanced Class you are.

 

Operatives do not use their rifle in their core rotation, you have to get in close and either DOT them up while within 10m, or if you are Concealment, you need to be within 4meters to knife them ot death.

 

Also keep in mind that apart from the turrets, you also need to deactive the sheild protecting the droids, or all your damage is wasted.

 

For a sniper, you can calmly sit back at 30m range and kill him to bits. Of course, just sitting there is a bad, bad, bad, idea, and you will need to move if an AOE falls on you. Aside from that, the rotation depends on your discipline, but they are rather intuitive, and I see now problem why you should not be able to faceroll the keyboard and come out victorious if you follow mechanics correctly.

 

If you have no advanced Class, well, I'd say you need more practice

 

Also, is your character geared at least to within 6 levels of that droid?

Set your companion as a tank, stand behind the droid and kill it. The companion, unlike a player, won't get 1-shotted by the 1-shot ability. Easily killable this way.

That works on the republic side.

 

Imperial fight is totally different.

Activate the turrets for extra damage.

On the upper level, activate the things that pour down lava / molten metal on the droid to get rid of the shield and for additional damage.

Watch out for adds, if they stack up, they can kill you.

And, of course, don't stand in stupid.

On my Sniper, I spent more time running around and activating things / killing adds, then actually fighting the droid.

So, I just did this fight as an Operative Imperial Agent. I set Vector to tank, sent him in to keep the boss occupied. Activated the databank to start the turrents, then went upstairs. The trick with the panels upstairs seems to stand about 10-15 feet away, wait for the aoe to target you, then run forward and click the panel. Do two of these, then go downstairs on the other side and activate the other turrent panel on the opposite side o f the room. From time to time, run into the middle and throw heals on Vector, then repeat.