I don't think there is any other private engineering college worth taking admission in, in Rajasthan, besides BITS. However, if you want the brass tacks, claiming JECRC is the best in the state may be a stretch.
Colleges such as Manipal University Jaipur and Amity University Jaipur tend to gain more popularity due to their wider appeal across the country. I personally wouldn't rate JECRC below MUJ or Amity, but neither do I find any reason to rank it higher.
JECRC Jaipur, in short, is a decent private engineering college in Jaipur, Period.