Looking at past trends in NEET counseling in Tamil Nadu:For Government Medical Colleges (GMC):

If you belong to the OBC category, it's typical for the cutoff to be over 500 marks. Given that you have 452 marks and an All India Rank of 118583, getting a seat in a Government Medical College under the state quota for OBC seems quite difficult.

For Private Medical Colleges (Management Quota or State Quota):With 452 marks, there might be a chance for your son at private medical colleges under the state quota, particularly in self-financed ones. The cutoff scores for these colleges tend to be lower compared to government colleges, and the OBC reservation can help increase the chances.

Estimating State Quota Rank (Tamil Nadu):With an All India Rank of 118583, the State Rank for OBC in Tamil Nadu might be around 5000-7000 based on previous years. However, this can change depending on how students perform this year and how many apply.