Please advice me the custom rom that use ram less than 600 mb , Battery Friendly and run stable
Seriously mate? First of all, you should probably read the
FAQ of this forum and specifically refer to Q8. Furthermore, there is another
forum for i9500 ROMs where you can find plenty of nice ROMs, just go through the threads, get the ROMs which appear adequate for your purposes and try them out.
I don´t mean to be rude but XDA is a forum for people who want to try out new things, educate themselves and understand better how certain mechanisms and processes related to hardware and software work. You are expected and need to do some reading and investigative research by yourself, otherwise you will not improve your knowledge and won´t advance at all as a user. If you are not eager to learn and don´t want to improve/advance, then clearly XDA forums are not for you and you are better served by other forums of which are plenty around. Excuse my directness but that´s pretty much it, I am sorry.