If you are fine travelling in break journey ..You can take CSMT-NED 07612/07613 csmt-ned on 16th + NED-ASR 04691 GNWL24 at 11AM which will confirm 100% from NED on 17th which will have better chances to get a berth in sleeper ...
Book it now itself..Else will have to wait till tomorrow morning for tatakal and try your luck