Vernacular press Act

ver·nac·u·lar (vər-năk'yə-lər)
n.
The standard native language of a country or locality.

The everyday language spoken by a people as distinguished from the literary language. See synonyms at dialect.
A variety of such everyday language specific to a social group or region: the vernaculars of New York City.
The idiom of a particular trade or profession: in the legal vernacular.
An idiomatic word, phrase, or expression.
The common, nonscientific name of a plant or animal.

thank you for the quick answer.

the comment was related to indian history.

i have made a conclusion based upon your comment....

here is mine conclusion

so, this vernacular means the language spoken by the native indian people.
and the govt wanted to put some restriction on their freedom of speech through newspapers written in vernaculars. so they made an act . that is a vernacular press Act

thank you