If you are planning to perform audits for certification bodies in Mexico, you should check with your accreditation body Entidad Mexicana de Acreditacion (EMA) on which auditor certification bodies are acceptable to EMA.
International Register of Certificated Auditors (IRCA) offers professional lead auditor certification after completion of an approve course and competence requirements. I have not heard of Regulatory Affairs Professional Society (RAPS) before and assume they offer auditor certifications similar to American Society for Quality (ASQ), Certified Quality Auditor (CQA).
If you are only looking for a professional certification then something like ASQ, CQA may be just fine but if you planning to work for a certification body, the IRCA certification is required.