I really really don't think so.
Without the magic of anti-gravity, a deployable-space-arcology has to fight the gravitational pull from the planet as well as burn-off its own massive kinetic energy from orbiting/interplanetary-travel.
That means it's going to need rockets. Big ones. And a load of fuel to boot. While I don't think it's plausible, I will spend the rest of this post making suggestions to make it slightly more plausible.
First, those rockets.
Lots of fuel means more weight, which means you need to more fuel to slow down that fuel. This is the classic rocket equation.
You can reduce the amount of fuel needed by blasting it out faster. This is difficult to do with chemical rockets - people have engineered them to their upper limits already.
Higher thrusts can be made from various types of nuclear and plasma thrusters.
ACME Arcology. Just add water.
Secondly, add agriculture, water, and (most importantly) people separately. Living things are fragile and squishy. Water is sturdy, but adds weight to the system. This allows the landing to be a little less gentle. Also, the heat from re-entry and your rockets won't cook everyone.
Some assembly required.
Finally, build the arcology in kit-form.
Deploying smaller sections and putting it all together at the destination is probably an easier task.
The larger the space ship, the more care you need to put into making sure the stresses and strains across the ship are balanced. This is most important when landing - otherwise it will break apart an scatter itself across the surface.