League of Legends (LoL) Question: Runes

9 yellow armor?

i tend to play rene. Your best bet is to get damage and mobility to shut them down and try to sustain when they poke you from too far to trade, like attempt to maintain the wave as much as possible. This being said, you want AD and CDR, ofc move speed and armor as well. Items wise id go for Hydra(which turns you into assassin when you are next to the ADC and will help you control the wave and not let it pushed at your turret), Ninja Tabis(just ADC counter by default) and Clever for the CDR, because you really need fast refreshment of your abilities in order to trade with the enemy

Greater Mark of Attack Damage
Greater Seal of Armor / Greater Seal of Scaling Health (armor vs physical if necessary)
Greater Glyph of Scaling Magic Resist / Greater Glyph of Magic Resist (flat MR vs magic)
Greater Quintessence of Attack Speed

On renekton it depends on the match up,
If you play blind pick, you won't know your opponent.
A standard page is the best in blind pick.
[*] 9x Attack Damage Marks (red runes)
[*] 9x Armor Seals (yellow runes)
[*] 9x Magic Resistance Gylphs (blue runes)
[*] 2x Attack Damage quintessence (purple runes)
[*] 1x Life steal quintessence (purple runes)
(NOTE: These can be changed based on your likings but this is what a standard page could look like)

In draft you can decide what to take against what opponent.
If your opponent is Attack damage (AD) you could go:
[*] 9x Attack damage marks (red runes)
[*] 9x Armor Seals (Yellow runes)
[*] 9x Scaling magic resist per level glyphs (Blue runes)
[*] 3x Attack damage marks (purple runes)

If your opponent is Magic Damage (AP) you could go:
[*] 9x Attack damage marks (red runes)
[*] 9x Health seals (yellow runes)
[*] 9x Magic resist glyphs (blue runes)
[*] 3x Attack damage marks (purple runes)

I hope this will help you out!
you can always search up a renekton on mobafire and get more optimal runes.
These runes are just standard based on any match up.
im sure you can get more optimal runes. but for that you should ask a true renekton main that knows the champion inside out.
to me these pages would work fine.
i think the power lays in the build, but the small advantages could be in your runes and masteries.

My opinion: these runes are optimal to me <3 hope this helps you!

First of all runes will be changed into a new system, if you will buy runes till then you will refund once the new system comes. But you won't be refund after Riot will lower the rune prices, but they will cost just 10 IP.

I don't recommend to use runes for a specific kind of champions, but the problem with range champion is their ability to easy trade and kite, I would say that defensive runes (include lifesteal) and mobility for longer fights or aggressive such as lethality for trying to one shoot them.

The main issue is that it can be fixed by better mechanics so I would recommend to watch the streamer and youtuber "Solorenectononly" he teach what be does while playing.

Runes will be removed soon so dont waste youre IP on thing thats not going to be able for you.