Muscat airport (MCT) is served by many international airlines. Visas are available on arrival (OMR5 / OMR20) for many nationalities. Please see ‘List 1’ at this site:
A number of nationalities are not covered by the visa on arrival arrangements. The conference committee is unfortunately unable to assist in this case, although a letter confirming registration and prepayment for the conference can be issued for accepted presenters only. Please contact your nearest Oman embassy to apply for a visa. Please note that airlines are unlikely to allow passengers to board if they are not in possession of a visa, or if their nationality is not on List 1.