Aphrodite
No. Terrible early + clear, easily shut down by a Curse.
Odin
Yes. Mana hungry and predictable, but has a devastating early and his ult is really powerful (esp. given its short CD)
Neith
Eh. Can be viable, but not really seen competitively because you'd be trading out a frontliner. Can work though, since she has the sustain and poke.
Scylla
Yes. Relatively solid clear, has an escape, and hits hard mid-late. The burst from her 1-2 is particularly notable.
Anubis
Not really. He's extremely powerful in terms of damage, but two of his abilities root him and he lacks mobility, so he'll be camped quite easily by a competent jungler.
He Bo
Possibly. While not as immobile as Anubis, his early-game damage is lacking enough that he can be shut down due to his lack of an immediate escape. Mid-late he really picks up, though; there's a reason we call him "The god with the 3 ults"
Khepri
Great support pick. Brings a lot to duo lane and his revive is invaluable. Do be careful when using Abduct, however, since you can still be AA'd during its duration.
Bacchus
Meh pick. His early clear is bad and most of his CC comes from the jump and ult, since his Belch takes a while to actually stun. Late-game, he's a heavy-hitting tank, but getting to that late-game is difficult considering the early-game meta and support being a very underfarmed role.
Odin
Eh. Not that viable, but possible; he lacks the peel potential that the other support picks have on all of his abilities save for his ult.
Nemesis
Viable. Her clear has gotten better in the new season, she has fairly decent sustain from her shield when used properly, and her anti-tank/pursuit potential are formidable.
Freya
No. Not viable. Takes too long to get online in terms of clear and is relatively immobile.
Awilix
Viable. Her early-game hits a lot harder than her late, but she has great mobility/gank potential, and her ult is devastating when coupled with other gods that can help her makes use of it (ex. He Bo Waterspout a backline squishy to get pulled by Awilix)
Freya
Viable. Hits hard, has a formidable late-game, and has decent clear. Couple that with a situationally useful ult, and she makes for a good ADC.
Xbalanque
Eh. Partially viable. His early-game clear is extremely mana-hungry so, while he does have incredible damage output because of his 1, he's also going to have great troubles in sustaining it. His global ult and CC-immune jump can't be ignored however, so it all depends on the comp.
Neith
Great pick. Has great clear, good sustain, a kill-securing ult (hehe), quick escape, and a very heavy-hitting early-game. She falls off somewhat around the late, but not enough to become irrelevant, especially given the damage and CC from her 1.
Note: By "viable" I mean "can be played"; this doesn't necessarily mean that you should play these gods at all times. It becomes increasingly difficult to play anyone but top picks as you climb the ranks.