Most of the Polytechnic Colleges offers admission on the basis of entrance examination. Now as you know firstly most of 10+2 or 10 examination board results aren't released.

Now for Polytechnic courses you have to appear for the entrance and no such entrance notification are out for such exams due to this covid 2nd wave situation. Last year no entrance were conducted in states like West Bengal for Polytechnic admission else was given on the basis of merit. So based on the situation improves and based on the decisions of the state government such exams will be conducted. So you can wait for sometime and you can obviously expect some notification by the end of this month.

To know more about the polytechnic entrances 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!