So, there is no direct correlation between your PCM marks to admission in RVCE, not for the merit seats anyway.
To get into any Bachelor’s program through merit in RV one needs to write the competitive entrance exams, KCET or Comed-K. The rankings obtained in these exams are dependent on your PCM scores plus the entrance exam scores. Depending on your ranking you can chose any of the branches of engineering whose cut-offs vary widely.
Here’s a link providing such trend:
RV College of Engineering, Bangalore
Although, I don’t think this is accurate.
There’s the management quota too which is a whole other deal altogether.
Hope this helps.