There isn't really a way to force JPEG and TIFF files to open in Camera Raw from the Organizer. The reason some files are opening in Camera Raw and others are not is because those that are opening in Camera Raw have been opened there previously. Once you open a JPEG or TIFF in Camera Raw, the file becomes tagged and will continue to open in Camera Raw. You can open groups of images in the Elements Editor in Camera Raw to give them this tag. Just use File > Open As, choose your files and set the format drop-down at the bottom to "Camera Raw" (Just use File > Open on Mac).
tks brett, but unable to select more than one file with "file>open as" i want to batch edit several files which are under exposed
tks again brett, i tried 1st part yr answer,opened each file in acr and cancelled, opened organizer where had selected files
, clkd "fix>full edit" and all opened in sidebar of acr as rqd. miracles still happen!
regards dave h