You will have to pay a fine for every day that you overstay in Oman.

You can go to Oman IE Visa to find more information regarding Oman tourist visas. 

You will receive your Oman visa through your mail or you can download it from the website. 

Your passport must have a minimum of 6 months of validity and a minimum of 4 blank pages in order to obtain an Oman visa.