Listen its not necessary that previous year marks cutoff would be the same this year too. So I would like to suggest you to score as much as you can and listen check previous years cutoff rank if you score rank inside it you will definitely get into the govt college because ranks don't vary mostly.

Hi Reshma, As per your query about marks cutoff.. I would like to tell you it varies very year... It depends on lots of factors like difficulty level of paper and number of students getting that mark etc... It also depends on whether you applying from All india quota 15% or State quota 85%... Cut off of state quota is usually lower than all india quota.... Now in each of these quota its further divided into categories like OPEN/SC/ST/OBC..... Etc..
But going by last year trends around 450 - 550 marks will be securing a seat in govt seat

Hopefully it helps

Regards
Dr Parmanand Agarwal
MBBS MD
Career counselor

Hii Reshma,
Assuming that u r general category,If u consider last year's NEET ranks,the minimum marks to get an admission in kerala is 835 and that goes to TD Medical college.Considering self financing college, the last rank is at 3362 ie in Sreenarayana Institute of medical science,Ernakulam.
Hope this helps.If uhave any further doubts pls feel free to ask..