As soon as you drop down, immediately take cover as more enemies emerge. If you need ammo during the upcoming fight, there are 5 bundles of arrows, 2 boxes of shotgun shells and 4 boxes of rifle/SMG ammo scattered around this area.
As far as tactics go, it's basically the same scenario as the last big fight. The Solarii on the other tower shoot at you with rifles and throw explosives. Shoot back with your long-range weapons, the bow and rifle, and release aim to make better use of cover when the hail of bullets gets too intense (as shown above).
Change position and take cover when you see incoming dynamite or Molotov cocktails.
Try and shoot the demolitions men as they're about to throw, making them fumble their dynamite and blow themselves up. Also, aim for the fuel barrels to blow up any nearby enemies. Here Lara hits a barrel near a demo man.
The barrel explodes...
...followed by the dynamite. Bonus!
Keep in mind that the enemies can do this too, so don't linger near the hazards on your side. If you want to move up to the metal crates at the front edge of the platform, destroy the fuel barrels there first.