You didn't mentioned the name of the college in which you wish to take admission. I would recommend that you need to give the entrance examination in which the college you are talking about participates. As most of the Polytechnics are state funded so you need to qualify the state polytechnic entrance to get admission in the polytechnics.

For more information regarding Polytechnic entrance in India visit the link below:

https://engineering.careers360.com/articles/polytechnic

I hope this answer helps. All the very best for your future endeavors!