The incident happened on Friday night in the hostel of a government-aided school at Bishnu Naha in Thoubal district.
"On March 18 night, the accused barged into the room where some of us were preparing for the next day's examination. He told us to go to our rooms. When I was the last person to leave the room he molested me and tried to rape," said the victim in her complaint.
"Luckily for me, one student saw what was happening and alerted others," she said.
The accused, Keisham Ibohanbi, 61, also threatened to harm her if she informed anyone of the incident, the victim said.
On Saturday, a Thoubal district court remanded Ibohanbi in police custody till March 22.
He has been charged under the provisions of the Protection of Children from Sexual Offences Act, 2012, police said.
The accused was not a recognised teacher and "surprisingly there is no female warden despite the fact that there are about 50 girls in the hostel," said police.
Students' organisations and women's vigilante groups have strongly condemned the "beastly act".
At least one students group declared that the accused would never be allowed to continue working as a teacher.