Rock rank gets the following commands:

[ROCK] Prefix in-game (In gray)

Receive an Aggron Pokemon!
Receive $500 in game!

Kits:

/Kit Rock (One Time Usage)
x1 Full Moon Stone Tools
x1 Rockium Z
x5 Rock Gem
x5 Smooth Rock
x2 Diamonds
x15 Iron Ingots
x10 Gold Ingots
x1 Enchantment Book: Unbreaking III
x16 Potions
x2 Ultra Balls
x8 Great Balls
x25 Poke Balls
x1 TM71: Stone Edge (Unova)
x1 TM48: Rock Tomb (Galarian)
x1 TM23: Smack Down (Kalos)
x1 TM76: Stealth Rock (Sinnoh)
x1 TM22: Rock Slide (Galarian)
x1 TM69: Rock Polish (Kalos)
x1 TM32: Sandstorm (Galarian)

Extra Perks/Commands:

Access to the Server when it's Full.
Access to 36 Vault Spaces. 
Access to /PokeHeal. (Heals your Pokémon!)
Access to /PC. (A virtual PC you can use anywhere!)
Access to /Top. (Teleports you to the top block above you!)
Access to /Thru. (Teleports you through walls!)
Access to /Warp Set. (Sets a warp to wherever you'd like!)
Access to /Sethome(3 Homes). (Sets a home. Use /home to see your homes!)
Access to /NightVision. (See at night without a potion!)

Grass rank gets the following commands:

[GRASS] Suffix in-game (In green)

Receive an Torterra Pokemon!
Receive $500 in game!

Kits:

/Kit Grass (One Time Usage)
x1 Full Leaf Stone Tools
x1 Grassium Z
x5 Grass Gem
x5 Leaf Stone
x2 Diamonds
x15 Iron Ingots
x10 Gold Ingots
x1 Enchantment Book: Unbreaking III
x16 Potions
x2 Ultra Balls
x8 Great Balls
x25 Poke Balls
x1 TM21: Mega Drain (Kanto)
x1 TM53: Energy Ball (Alolan)
x1 TM86: Grass Knot (Alolan)
x1 TM28: Giga Drain (Galarian)
x1 TM11: Solar Beam (Galarian)
x1 TM50: Bullet Seed (Galarian)

Extra Perks/Commands:

Access to the Server when it's Full.
Access to 36 Vault Spaces.
Access to /PokeHeal. (Heals your Pokémon!)
Access to /PC. (A virtual PC you can use anywhere!)
Access to /Top. (Teleports you to the top block above you!)
Access to /Thru. (Teleports you through walls!)
Access to /Warp Set. (Sets a warp to wherever you'd like!)
Access to /Sethome(3 Homes). (Sets a home. Use /home to see your homes!)
Access to /NightVision. (See at night without a potion!)

Ice rank gets the following commands:

[ICE] Prefix in-game (In aqua)

Receive an Lapras Pokemon!
Receive $500 in game!

Kits:

/Kit Ice (One Time Usage)
x1 Full Crystal Tools
x1 Icium Z
x5 Ice Gem
x5 Ice Stone
x2 Diamonds
x15 Iron Ingots
x10 Gold Ingots
x1 Enchantment Book: Unbreaking III
x16 Potions
x2 Ultra Balls
x8 Great Balls
x25 Poke Balls
x1 TM79: Frost Breath (Kalos)
x1 TM70: Aurora Veil (Alolan)
x1 TM27: Icy Wind (Galarian)
x1 TM35: Hail (Galarian)
X1 TM13: Ice Beam (Kalos)
x1 TM14: Blizzard (Kalos)

Extra Perks/Commands:

Access to the Server when it's Full.
Access to 36 Vault Spaces.
Access to /PokeHeal. (Heals your Pokémon!)
Access to /PC. (A virtual PC you can use anywhere!)
Access to /Top. (Teleports you to the top block above you!)
Access to /Thru. (Teleports you through walls!)
Access to /Warp Set. (Sets a warp to wherever you'd like!)
Access to /Sethome(3 Homes). (Sets a home. Use /home to see your homes!)
Access to /NightVision. (See at night without a potion!)