Go for Rajarajeshwari College Bangalore, since it is one of the top 10 private colleges of karnataka, whereas in terms of ranking Siddhartha Medical is quite down the list. Also, considering that Rajarajeshwari college is in Bangalore, you will get a much better exposure in terms of practical knowledge in Bangalore rather than vijayvada, since you will get to see more number and variety of cases in Bangalore. Also, in terms of teaching pedagogy and college life once again Rajarajeswari college is better as compared to Siddhartha Medical College.