Best support for low elo - Nautilus, leona or braum
Need a good support out of those 3.
Need a good support out of those 3.
its not the champion that matters, its the player. 
depends on what you consider as low, and how low exactly.
if you mean 'bottom of the barrel' low, id probably go with blitz. at least if you dont suck donkey dick yourself.
around mid silver, low gold, id probably go with nautilus or leona. from there on, pretty much always thresh.
I'd say leona. She loses to Naut directly but most in lower elos can read and respond to a freindly leona's engage more readily than a nautilus one, which is what counts. If they first pick leona on you, take Naut and dare her to engage, because not much is funnier as a support than an enemy leona realizing her mistake.
I'd go with Braum because instead of having to initiate and rely on your teammates to follow up, all you gotta do is protect your adc/teammates.