Hello Saroj,

        See its always difficult to predict and almost seems meaningless to predict the exact college to get admission into as the trend for cutoff of each college changes every year. 

         The cutoff for every college or exam depends on two main factors :

    performance of students 

    no. of seat's available 

    Compared to last year's cutoff for St. Johns Medical College Bangalore the cutoff rank was around 1500 to 1600  for all India open quota so if with this rank you are able to come under 1500 rank u may get into this college. 

Below is the link for predicting college with rank and category you may try it once:

https://medicine.careers360.com/neet-college-predictor

  Good Luck