Your better contractual benefits will apply. Article 6 of Law No. 6 of 2010 establishes that the provisions of the law represent the minimum standard for worker rights. If your individual employment contract, a collective agreement, a company policy, or even established trade custom provides you with more favourable terms, those better terms take precedence.
This is a vital protection for expats in Kuwait: the law acts as a floor, not a ceiling. For example, if the law sets a minimum annual leave entitlement but your contract offers more, your employer must honour the contractual entitlement. Conversely, your employer cannot use a contract to give you less than what the law guarantees — any contractual clause that does so is legally void.
Practically speaking, always keep a signed copy of your employment contract and any company HR handbooks. If a dispute arises, both the law and any superior contractual benefits are enforceable. If you believe your employer is breaching either, you can file a complaint with the Public Authority for Manpower in Kuwait.
This is general legal information, not legal advice. For advice on your specific situation, consult a lawyer licensed in Kuwait.