See there are many things

(1) First thing is...Analyzing selection on the basis of Marks is not a reliable criteria because it depends upon the level of questions in the paper, rather on the basis of rank is more stable thing.

(2) Second thing is category .. As for instance in bihar in 2018 last govt mbbs seat, Rank for

General - 11.1k(534),

BC -15k(517)

EBC -21k (500).

Reference - bihar second counselling 2018 allotment list , you can check it yourself, link for pdf is below.

If you apply these datas to this year

11k-approx 585 ,

15k -approx 572 ,

21k- approx 555

but ranks may slightly vary. (See these vast differences , this is the main reason of mess …)

PS-These are only appoximations not accurate datas so if your marks are slightly less , donot panic, have hope.

(3) Third thing , allotment of seats also varies year after year.. (How much students are going out of the state, which also depends on seats available through all India counselling)...

As this year slightly some seats have increased overall in all India quota , so we can expect a slightly lower competition , although in 2018 seats increased at all India level but due to Rajasthan domicile issue much more students did not went out of bihar as they took most of the seats in PMCH and different colleges ; which caused good competition on the seats. It affected the last rank at which PMCH is alloted through state counselling , The last rank decreased to some extent.

This year inclusion of EWS may also affect the cuttoff.

You can do your own better assessment on the basis of previous year trends, for which you have to check previous year allotment results of last counselling but you have to wait for merit list of bihar as trends are not much constant every year.