The Odtantpuri education center was situated in Bhar. It is important to note that Bhar refers to the ancient kingdom of Bharatavarsha, which is believed to be located in present-day India. Bengal, Gujarat, and Tamil Nadu are all states in modern-day India, but they are not the correct answer in this case. The correct answer provided is option 3 - Bhar. It is worth mentioning that Odtantpuri was an important center of learning during ancient times and had significant contributions to education and knowledge.