What it is like here
Oman’s vocational colleges are an arm of Omanisation: their purpose is to qualify Omani nationals for jobs currently held by expatriates. That is a legitimate national policy and it is squarely against the interest of a foreign trainee. No international rate is published, and the trades a certificate leads to are the ones being closed.
How the process works
Check whether the college admits non-Omanis at all
The admission criteria are written for nationals and say nothing about anyone else.