Dear Karthik

The Directorate of Medical Education (DME), Tamil Nadu will conduct the counselling for admission to postgraduate courses in private medical colleges in Tamil Nadu. The admission will be conducted on the basis of NEET PG 2018 scores and All India NEET PG 2018 Rank. The application forms for registering for Tamil Nadu postgraduate medical counselling will most likely begin in the last week of March 2018. Prior to that, DME, Tamil Nadu will also release a brochure or admission notification detailing everything about private medical college admission counselling. 

You can also check more details about procedure of private colleges PG counselling in Tamil Nadu from the link given below: 

Tamil Nadu PG Medical Counselling 2018

I hope it clears your query. All the best!