Sri Ramakrishna Mission School, has many branches across Chennai and similar schools across India.
They have boys school, a girls school called as Sri RKM Sarada Vidyalaya.
The mission itself is in existence from 1897 onwards founded by Swami Vivekananda. And has 114 centres in India and about 50 centres outside india (in places like Singapore, Durban etc.) all under the HQ at belur Math near Kolkatta.