Hello,
To qualify in NEET, a General Category candidate has to score 50% of the top NEET score. For example, if the top NEET scorer has scored 500, General Category candidates should score atleast 250.

Now not every qualified candidate can get a medical seat. It depends on cut offs. Now cut offs change every year and are dependant on various factors like no.of seats available, no.of candidates appearing for the exam, difficulty of the exam and top NEET score. Every State except Jammu and Kashmir has All India Quota and State Quota and there is different cut off for each quota. Now every State has various cut offs for every college and Category. Tamilnadu is one of the States with highest cut off. But States like Assam do not have that high cut off. So it totally depends on what State you want to apply and if you want to apply under All India Quota or State Quota. State Quota has higher cut off marks. Neverthless, anything less than 550 in General is less. For Tamilnadu, it should be atleast 625. But for Himachal Pradesh it is around 300.