I asked regarding pgimer chandigarg

In reply to science technology:

There are two sessions one in each January and July. There's no December session.
The official dates are not released yet.
It's advicable to follow their Official website.

For a tentative schedule you refer the following link :
https://www.google.co.in/amp/s/medicine.careers360.com/articles/pgimer-application-form/amp

All the best!