There isnt any hardcore rule, but a wild guess can be like:
SL: CKWL - 35-40
3A: CKWL - 2-7
2A: CKWL - 1-3
PS: These arnt fixed, as cancellation & unutilied Quotas can lead...
more... to clearance of Higher WL, while in case of lesser cancellation & utilization of Quotas would lead to non-clearance of lower WL!!!