my neet 2019 score is 502 and i belong to OC category. do i have a chance to get admission in a government medical college in Tamil Nadu?

Hey !!
The chances of getting into government medical colleges is quite rare. However you can try for private colleges through government quota or private quota also. You have chances of getting admission in later rounds of counselling. However if there is no admission and if your only passion is medicine then you can drop out a year and prepare hard.
I have shared a link below which could give you idea on cutoffs and colleges
https://medicine.careers360.com/articles/neet-cut-off-for-government-colleges
Don't lose hope !!
Best of Luck !!