Religious Orders are not of different religion. They are group of Priests or Nuns who practice Catholicism but with certain different methods on how they apply their faith and belief. Some of them adopt the monastic way where they live in monasteries like the Benedictines, some adopt the hermetic way where they isolate themselves from the society like the Carthusians, some adopt the mendicant way where they beg and give service to the poor like the Franciscans, rebuilding churches like the Redemptorists, gives education to the youth like the Salesians and some are building schools and Hospitals like the Sisters of Charity.
The religious orders are mostly known by their founders, like the he first religious order in the history, the Order of Saint Benedict (Benedictines) which was founded by Saint Benedict of Nursia, the Order of Preachers (Dominicans) by Saint Dominic, the Order of Friars Minor (Franciscans) by Saint Francis, the Society of Jesus (Jesuits) by Saint Ignatius of Loyola, Congregation of the Most Holy Redeemer (Redemptorists) by Saint Alphonsus Liguori, Sisters of Charity by Saint Elizabeth Ann Seton and the Salesians of Don Bosco (Salesians) by Saint John Bosco. Though these Religious orders have different ways, they did not leave the Catholic Church. Their faith still lives in the Catholic Church because they know the one and true church that Christ has built. Not only they have the same faith and belief, they also help the poor, educated the faithful including the Children and helped the people who were lost or confused about their faith. But there’s one way that unites these religious orders, where the all the clergy wear the same clothes and do the same act, and that it is the Holy Mass.
Now we encounter some of the latest Catholic Religious orders like the Opus Dei by Saint Josemaria Escriva, Missionaries of Charity by Saint Mother Teresa of Calcutta who helps the destitute and dying and the Society of Saint Pius X by Archbishop Lefebvre, who preserves the Traditional Mass. Even though they have their differences, what matters is their belief. Because the church is one, holy, catholic and apostolic that united by God.