The Sunni are the majority of the Muslim nation. They are the people who rightfully followed the methodology of Prophet Muhammad (May the peace and blessings of Allah be upon him). They include the companions and those who followed them in the essence of belief. They are the people referred to in the Hadith of the Messenger of Allah when he said what means:
“Let the one who seeks the vastness of Paradise remain steadfast to the majority.”
The Sunni Muslims are the majority of true followers of Prophet Muhammad (may the peace and blessings of Allah be upon him). It happened that after the year 260 after Hijrah, perverted innovative beliefs of some adherents to Islam emerged leading to the splitting of Islam into sects as prophesized by Prophet Muhammad.
Oman is one of the countries that house many of the major sects in Islam such as the Sunni sect (the true followers of Islam), the Shia and the Ibaadiyya. Ibaadiya is the official sect in Oman with the ruling Sultanate being Ibaadis.
Unlike in some other countries in the region, in Oman the different branches of Islam live peacefully with one another. In many ways Oman is a throwback to an earlier time when adherence to one sect or another was a personal matter. Residents here often don't know the religious affiliation of their neighbors.
While the government doesn't publish statistics on religious affiliation, best estimates indicate about 50 percent of the country's 2.25 million Omanis are of the Ibadi faith.
The Ibadi branch of Islam, also known as the “third branch,” was established over 1,300 years ago, predating Islam’s split between Sunni and Shia after Prophet Muhammad’s death. Sunnis constitute another 45 percent of the population, while most of the rest are Shia.
Omanis have a long history of religious tolerance. The Shia minority doesn't face discrimination by the majority Ibadis or larger minority Sunnis. But that equanimity comes at a price. Suspected religious extremists, indeed all dissidents, face sharp repression under the authoritarian rule of Sultan Qaboos bin Said al Said.1
However, Some sources mentioned that the Ibaadiya Sultanate of Oman put a lot of restraint on the Sunnis in Oman. The Ministry of Islamic Affairs in Oman which is mostly dominated by adherents of the Ibaadi misguided sect turn many sunni mosques into Ibaadiya ones. Books on sunni literature especially those written on the true Islamic theology (Aqeeda) are prevented from circulating. Matters even reached to an extent that copies of the glorious Qur’an were denied from entering Oman because they were printed in Saudi Arabia.
In addition, the true and well-learned Sunni scholars are not allowed to enter into the country for lectures and seminars. Sunni students and scholars in Oman are not also allowed to give lectures to their Sunni congregation, most lectures in major Sunni mosques are conducted by Ibaadiyya scholars with the support of the Ministry of Islamic Affairs.
According to sheikh Mamduh Al-Harbi; a scholar specialist in religions and sects in an article about a research he conducted that: “the Sunni Muslims in Oman occupy a majority percentage of 75, but are made subservient by the ruling Ibaadi class in an extent that, they fear to make known their identity.2
It must however be mentioned that, besides these secret and indirect efforts to weaken the spread of Sunni ideology of Islam, the different sects lived in harmony without any recorded strife ignited by religious sentiments among them. This peaceful co-existence existed also among the Sunni Muslims and the other minority non-Muslim religions in the country such as Christianity, Buddhism and the rest.
2-the condition of Ahlu-Sunna wal-Jama’ with Ibaadis in Oman (http://www.alabadyah.com/showthread1.php?id=93)