They should not wear revealing blouses and needed to be dressed decently, the code said.
State education secretary K. Lalnghinglova said the government would soon come out with the code, which would include ethics of teachers and students alike in all government-run educational institutions.
Under this code, teachers who are found using drugs or alcohol will be punished.
Smoking on the school premises is to be strictly prohibited for teachers and will be a punishable offence.
Students smoking and chewing paan will also be punished and sending students to buy cigarettes and paan will be considered punishable.
Male teachers should not come to teach in their shorts, T-shirts or in chappals.
He said the code of ethics and dress code for both teachers and students would soon be published and enforced by the state government.
However, some teachers said this new effort by the government was regressive.
It was also defamatory for teachers, who were always decently and formally dressed, as befitting to their role as instructors of children.
They said many schools already have uniforms for teachers, which they diligently wear everyday.
As for puan, women teachers have not given up the practice of wearing it.