30level cap
Rocket Admin Sierra (Rocket Hideout) fields 5 Pokémon between level 29 and level 30 in Rocket Hideout.
This is around Thunder Badge — Rock Tunnel to Celadon City in the story — that page lists everything you can have caught by this point.
Types on this team: Psychic ×2DarkFireGrassIcePoisonWater
| Pokémon | Ability & item | Moves | Base stats | |
|---|---|---|---|---|
 | Hypno Lv 29 PsychicDark | Ability Insomnia Held item Quick Claw Lax nature | Psybeam Frustration Secret Power Disable | HP85Attack78Defense85Sp. Atk93Sp. Def115Speed67Total523 |
 | Kadabra Lv 29 Psychic | Ability Synchronize Held item TwistedSpoon Modest nature | Psychic ThunderPunch Recover Reflect | HP40Attack35Defense30Sp. Atk115Sp. Def70Speed105Total395 |
 | Victreebel Lv 29 GrassPoison | Ability Intimidate Held item Poison Barb Sassy nature | Stun Spore Leaf Blade Sleep Powder Poison Fang | HP100Attack110Defense65Sp. Atk95Sp. Def60Speed80Total510 |
 | Lapras Lv 30 WaterIce | Ability Shell Armor Held item Sitrus Berry Hasty nature | Icy Wind Water Pulse Body Slam Confuse Ray | HP110Attack70Defense80Sp. Atk85Sp. Def95Speed60Total500 |
 | Ninetales Lv 29 Fire | Ability Flash Fire Held item Charcoal Modest nature | Flamethrower Will-O-Wisp Psychic Quick Attack | HP73Attack76Defense75Sp. Atk91Sp. Def110Speed100Total525 |
How to beat this team
Shared weaknesses. Bug hits 2 of 5, Rock hits 2 of 5, Dark hits 1 of 5, Electric hits 1 of 5.
Level to be ready for. Lv 30 — Lapras, the highest on the team.
Bug Pokémon you can have caught by this point. From this guide’s own encounter tables, by Thunder Badge — Rock Tunnel to Celadon City: