You need an embassy visa for Oman if you have a Mexican passport
Visa options for Oman
Electronic visitor visa may be available with conditions
Travelers with a valid Schengen visa or a valid visa for United States, United Kingdom, Canada, Australia or Japan can apply online for an eVisa. An Oman eVisa is the fastest and easiest way of obtaining a visa for Oman because travelers can submit their application and supporting documents online. Once the application is approved, travelers receive their eVisa confirmation electronically.