Hello dear, as you are asking about opening and closing rank then I want to say that Opening rank is the rank at which admission to a particular Institute starts or open and closing rank is the rank at which the last candidate is alloted a seat.So, you can say that closing rank is the cut off rank and rank better then closing rank will definitely fetch you a seat in that particular Institute and Branch.Also the CRL rank is the COMMON Rank list which means your GENERAL rank under no category.
Hope i am clear to you.

hello,

Every year the cutoff changes as the level of the paper and many other factors change,so there is no certaunty for this .

You can check the previous years cutoff to get better idea.

Generally the crl is shown in the cutoffs but after the counselling is done the experts sort the ranking according to the category .

Best wishes 

Hello Mohan, All the closing rank and opening ranks mentioned in the Official cutoff list of JOSAA are CRL(Common rank list) which means all India open category rank. You can find the category wise rank separately but the cutoffs mentioned in JOSAA list are strictly CRL.