Wikipedia
The term Ojha or Oza is a surname for Hindu Sikhwal Brahmins, Shrimali Brahmins, Atri Gotra Brahmin, Saraswat Brahmin, Bhumihar Brahmins, Kanya Kubj Brahmin, Maithil Brahmin of Nepal, Nepali, Nagar Brahmin, and Bengali Brahmin of India and Nepal Ojhas are considered to be worshipers of Goddesses Durga, Saraswati, , Lord Hanuman and Lord Shiva. The surname is used amongst speakers of Nepali, Bhojpuri, Gujarati, Rajasthani, Hindi, Oriya, Maithili, Kumaoni and Bengali as well as amongst the Santhals. The high population of Ojhas are found in Central Nepal, and in India within districts of Gonda, Gorakhpur, Pithoragarh district, Uttarakhand, Pratapgarh, Ballia of Uttar Pradesh, Buxar ( Bihar), and Ara ( Bihar).
The term Ojha is derived from Sanskrit. Literal translations vary, but one meaning is "he who controls the spirits on Earth". According to some, the Ojhas were the top class Brahmin preachers who earned their livelihood through teaching. In Bihar, some consider Jha and Ojha to be the same clan. The Jhas are Maithilis originated in Nepal in Janakpura and call their sons-in-laws Ojhajis. This has given credence to this belief.
Ojhas are basically divided into two parts – Ojha and the Bavan-gaon ke Ojhas (the Ojhas of the 52 villages), as they got 52 villages in charity from one of Uttar Pradesh-region rulers for having protected those rulers by fighting themselves. They were also given the title of 'Singh' for the valour and aggression with which they fought. Mata Kaalratri is the Kuldevi of the Bavan-gaon ke Ojhas. Some Ojhas in Bihar have become Bhumihars, and usually use Singh or Sinha as their surnames. Some although have not become Bhumihars but still have the title of Singh – to use it or not to use is individual choice.
Ojha Brahmin from Uttar Pradesh had excellence in Martial Art, Spirituality, Veda and Science. They have many sub-branches under the surname Ojha. A sub- branch is known as Khairi Ojha which played a significant role in Indian history. Kairi Ojha are active in shaping and binding Hindu rituals and knowledge before the Shankaracharya and formation of “ Four Mathh” Sathapna. Khairi Ojha were spiritual leader for uttar Pradesh and Bihar region. They perform as “Rajguru”, “Army Trainer”, “Thinker” and Philosopher. In few parts of India Ojha ware ruling the Riyasats.
The Ojha of Nepal Brahmins are mainly vegetarians, non-drinkers and non-smokers.
As Brahmins, the Ojhas are spiritual leaders, teachers, and members of the highest ritual rank in the varna system of Hinduism.
Most of the Ojhas are concentrated in the Uttar Pradesh & Bihar (India) and Nepal, a few in Mauritius and can also be found in many regions of India and all over world.