You should prefer RUHS Jaipur. It has a good hospital attachment. In terms of academics, infrastructure, co-curricular activities, etc. it is a good option. It is a new college but has a higher cutoff. RUHS has a locational advantage as well. Jaipur has better PG coaching centers. These are some of the reasons that make RUHS a better choice.
MBBS is almost the same everywhere and it mostly depends on the students as they have to study mostly on their own.
In terms of academics, RUHS Jaipur would be the best option among the mentioned, without any second thought. The city also matters to an extent, and Jaipur is the best among them. The coachings for PG are mostly located in Jaipur and Udaipur. But if you are willing to travel up and down every weekend, then you can choose other cities.
I have friends from all three of these institutes and according to their reviews, here is the preference order that I will suggest.
RUHS Jaipur>RNT Udaipur>SN Jodhpur
But ultimately irrespective of which institute you are choosing, you will need to work hard to excel.