Ok so ill say right now that some classes get more PVP DMG Res or more Damage Res than other classes so use this info and make adjustments that best suite your class.
PVP DMG Res Cap : 75%
Damage Res Cap 75% (100% in PvE with class buffs)
Items Needed for PVP DMG Res / Damage Res
Offensive / Defensive Wings: 12% PVP DMG Res / 11% Damage Res
Costume Crests: x2 8% PVP DMG Res (Blue Crest), 13% PVP DMG Res Orange Crest
Aegis Moon Star Earrings: 4% PVP DMG Res / 3% Damage Res
White Candy Earring: 5% PVP DMG Res / 5% Damage Res
Rare Chaotic Necklace: 3% PVP DMG Res / 7% Damage Res
Sailor Ring ranges from 3-7% PVP DMG Res (Need Minimum 5% for max PVP DMG Res)
Helpyron's Belt +10: 6% PVP DMG Res / 4% Damage Res (An addition 6-8% PVP DMG Res can be added to belt with Immortal Reduce 3/4% Stones) Minimum Need x2 3% Immortal Reduce gems for Max* (3% Immortal Reduce is very cheap) Rank Option can also add 2/3% Damage Res
PVP Pet 5% PVP DMG Res (Duex or Dino)
Great Devil's Horn: 10% Damage Res
Perpetus: 15% Damage Res
Mc3 +10: 5% Damage Res
Helion Set Effect: 3% Damage Res
In Total: PVP DMG Res = 75% / Damage Res = 66%
Here is from the stat sheet of a Summoner. Summoner has a buff that gives 25% Damage Res which will hit the cap in pvp of 75%. I hope this helped, this is for new players trying to find a way to max PVP DMG Res and Damage Res.
for the classes that have PVP DMG Res Built in their kits, they can use the 9% Damage Res Blue or 11% Damage Res Orange to cap Damage Res