Dear Dibakar, with 50% in your 10+2 in Physics, Chemistry and Biology you are eligible for appearing for NEET because for Candidates belonging to ST Category, the required aggregate is 40%. Regarding marks required to secure a seat in a GMC in Odisha, we do not have 2019 data yet. In 2018, under State Quota, 281 marks secured a seat in GMC, Balasore under ST Category. That was the cut off. Now, cut offs change every year and are dependant on various factors such as Candidates appearing for NEET, Candidates qualified for NEET, top NEET score and difficulty of  the exam. In 2019, the individual cut offs increased by 60-75 marks on an average. So your target should be atleast 400 marks to secure a seat in a Government Medical College.