You haven't mentioned your Category. In 2018, under State Quota, 558 marks secured a seat in GMC Manjeri under General Category. That was the cut off. Now that is 2018 data and you will need atleast 625 in NEET 2020 if you belong to General Category and if you belong to any of the Reserved Categories, you will need atleast 550 and above. This is based on previous years data. Now Cut offs change every year depending on various factors such as no.of Candidates appearing for the exam, no.of Candidates qualified, top NEET score and difficulty of the exam. To help you with your NEET preparation, we have NEET Knockout packages that you can check at: https://learn.careers360.com/knockout-neet-may/. To help you during admission and counselling, we have https://www.careers360.com/mbbs-companion.