Can iv antibiotics & iv saline be given simultaneously if so what is the system called do 2 tubes from 2 bags go into a single tube going to a canulla?

Yes they can: You can run an antibiotic in saline with its own tube into a needle or you can have an IV maintenance saline solution with its tubing and run the IV antibiotic into the saline tubing so that only went to is going into the needle. Both ways of running an anabiotic are very common.

Yes: Yes, fluids and antibiotics can be given together, though there are some compatibility issues with certain medications. Your physician may choose to put the fluids through one line (maybe the left arm) and the antibiotic through another (maybe the right arm), or may choose to use a Y-connector to allow both to flow through a single IV catheter.