hey ramya 

with 230 marks and belonging to st category you might not get govt college in tamil nadu. as per previous year the cutt off of tamil nadu under state quota was more than 530 marks for st category. however we are not sure about this year cut off as it changes every yeear depending on no.of candidates, no.of seats and difficulty of exam.  

to predict colleges on the basis of yur neet score visit following link https://medicine.careers360.com/neet-college-predictor?icn=neet_clgpd_landing_page&ici=clevertap-sticky-web 

goodluck 

Hii !!
I am sorry to say you that the chances of getting into government medical or dental colleges is quite rare. You must have to score minimum of 300 marks atleast. However you can try private medical colleges through management quota or drop out a year and prepare for a year.
I have shared a link below which gives you fine detaiks about the government colleges and its cutoff
https://medicine.careers360.com/articles/neet-cut-off-for-government-colleges
Don't lose hope !!
Best of Luck !!

Dear Sujitha, 230 is a less score to be honest with you. In 2017 under State Qyota, 168 marks secured a seat in Rajah Mutiah Medical College under ST Category. We do not have 2018 cut offs handy. Even if it went upto 200 in 2018, with 230 as a score, its a very close call. You might get a seat in Rajah Mutiah Medical College. Having said that, cut offs change every year and are dependant on various factors like no.of seats availble, no.of candidates appearing for the exam, top NEET score and difficulty of the exam.