Here are companies (brands) that produce complete, balanced diets specifically formulated for indoor cats (products widely available in Australia). I’ve listed each brand with a short note and a source you can check for the indoor‑cat formula.

• Royal Canin — Royal Canin Indoor (dry diets formulated for adult indoor cats: moderate calories, hairball control, highly digestible protein). (royalcanin.com)

• Hill’s (Hill’s Science Diet) — Hill’s Science Diet Indoor (wet and dry indoor formulas targeting digestion, weight control and litter‑box clean‑up). (hillspet.com.au)

• Purina (Purina Pro Plan / PURINA ONE) — Purina Pro Plan Indoor Hairball Control and PURINA ONE Indoor Advantage (indoor formulas for hairball control, reduced calories and digestive support). (purina.com.au)

• Wellness (Wellness CORE) — Wellness CORE Indoor formulas (grain‑free indoor recipes with added joint and skin support nutrients). (wellnesspetfood.com.au)

• Blue Buffalo — Blue Buffalo indoor formulas (indoor/weight‑management-focused dry diets with LifeSource Bits / antioxidant blends). (amazon.com.au)

• IAMS — IAMS ProActive Health Indoor Weight & Hairball Care (formulated for weight control, hairball management and complete nutrition). (iams.com)

• Orijen (Champion Petfoods) — ORIJEN produces high‑protein cat diets (available in Australia through local distribution; check product lines for indoor‑targeted formulas or high‑protein balanced options). (petroom.com.au)

Notes and quick tips

• “Complete and balanced” on a product label means the formula meets nutrient profiles for maintenance or the life stage claimed (check the bag or product page for the AAFCO/FSANZ/other statement). Most major brands explicitly label indoor formulas as “complete and balanced.” (royalcanin.com)
• Indoor formulas typically focus on lower calories, higher fibre (hairball control), urinary/weight management and digestibility — but formulations differ between brands; compare ingredient lists and guaranteed analysis if you have specific concerns (weight, allergies, urinary disease). (royalcanin.com)
• If your cat has medical issues (urinary crystals, kidney disease, obesity, diabetes), consult your veterinarian before switching diets — prescription diets may be required.

If you’d like, I can:

• compare 2–3 specific indoor formulas (nutrition panels and calorie content), or
• find where to buy any of these brands near you in Australia (online retailers / local pet stores).