If the coil was faulty, the whole lot would be affected, not just missing on one cylinder.
Get a working spark plug (not from your car but same / similar type) and cut the bent bit next to the electrode off. Disconnect the HT lead from one of the spark plugs and connect it to the 'Test plug'. Cutting the bent electrode bit off increases the distance the spark has to jump, replicating the inside of the combustion chamber when under compression.
Use this to test each lead to each plug by earthing the body to the engine.
You want to crank it, but not start it, so you can remove a relay for the fuel system to prevent it from starting.
If the spark at the end of a lead is nice and clear and consistent, then that lead is good.
Do it to all 6.
Check the dizzy cap for tracking (carbon build-up) inside and any cracks or lines. This can cause the spark to run down the cap and earth, instead of the HT lead.
Check all injector electrical connections to ensure they are functioning.
Make sure each injector is firing by using an LED test light on the wiring. It should flash each time it is active.
Not sure if the choke is auto or manual or how it functions but that would be the other idea.
I'd consider checking the inlet, air filter and possibly manifold for carbon build-up and also the blow-by to see if there are other contributing issues