Shell Programming and Scripting

$ cat x.csv
baseball,NULL,8798765,Most played,0,5,12367,NULL,NULL,98,67,Reason is not sufficient
baseball,NULL,8928192,Most played,0,4,76893,NULL,RAW,54,78,NULL
baseball,NULL,5678945,Most played,9,2,1,6,NULL,6789,123,Reason not conclueded
cricket,NOTNULL,125782,Usually played,NULL,NULL,NULL,NULL,123,67,NULL
cricket,NOTNULL,678921,Usually played,NULL,NULL,NULL,NULL,563,NULL,Reason not defines
$ sed 's/NULL/ /g' x.csv
baseball, ,8798765,Most played,0,5,12367, , ,98,67,Reason is not sufficient
baseball, ,8928192,Most played,0,4,76893, ,RAW,54,78,
baseball, ,5678945,Most played,9,2,1,6, ,6789,123,Reason not conclueded
cricket,NOT ,125782,Usually played, , , , ,123,67,
cricket,NOT ,678921,Usually played, , , , ,563, ,Reason not defines
$

sed 's/NULL,/,/g' inputfile

$ ruby -F"," -ane 'print "#{ $F[0..-2].each{|x| x.gsub!(/NULL/i,"")}.join(",")},#{$F[-1]}" ' file
baseball,,8798765,Most played,0,5,12367,,,98,67,Reason is not sufficient
baseball,,8928192,Most played,0,4,76893,,RAW,54,78,NULL
baseball,,5678945,Most played,9,2,1,6,,6789,123,Reason not conclueded
cricket,NOT,125782,Usually played,,,,,123,67,NULL
cricket,NOT,678921,Usually played,,,,,563,,Reason not defines

Thanks Pravin.
But can you check the second row, last column.
The code will delete that also
$ cat x.csv
baseball,NULL,8798765,Most played,0,5,12367,NULL,NULL,98,67,Reason is not sufficient
baseball,NULL,8928192,Most played,0,4,76893,NULL,RAW,54,78,value is NULL,value expected
baseball,NULL,5678945,Most played,9,2,1,6,NULL,6789,123,Reason not conclueded
cricket,NOTNULL,125782,Usually played,NULL,NULL,NULL,NULL,123,67,NULL
cricket,NOTNULL,678921,Usually played,NULL,NULL,NULL,NULL,563,NULL,Reason not defines
$ sed 's/NULL,/,/g' x.csv
baseball,,8798765,Most played,0,5,12367,,,98,67,Reason is not sufficient
baseball,,8928192,Most played,0,4,76893,,RAW,54,78,value is ,value expected
baseball,,5678945,Most played,9,2,1,6,,6789,123,Reason not conclueded
cricket,NOT,125782,Usually played,,,,,123,67,NULL
cricket,NOT,678921,Usually played,,,,,563,,Reason not defines

sed 's/,NULL,/,,/g' x.csv

$ ruby -F"," -ane 'print "#{ $F[0..-2].each{|x| x.gsub!(/NULL/i,"")}.join(",")},#{$F[-1]}" ' file
baseball,,8798765,Most played,0,5,12367,,,98,67,Reason is not sufficient
baseball,,8928192,Most played,0,4,76893,,RAW,54,78,value is ,value expected
baseball,,5678945,Most played,9,2,1,6,,6789,123,Reason not conclueded
cricket,NOT,125782,Usually played,,,,,123,67,NULL
cricket,NOT,678921,Usually played,,,,,563,,Reason not defines

# sed 's/,NULL,/,/g' file
baseball,8798765,Most played,0,5,12367,NULL,98,67,Reason is not sufficient
baseball,8928192,Most played,0,4,76893,RAW,54,78,value is NULL,value expected
baseball,5678945,Most played,9,2,1,6,6789,123,Reason not conclueded
cricket,NOTNULL,125782,Usually played,NULL,NULL,123,67,NULL
cricket,NOTNULL,678921,Usually played,NULL,NULL,563,Reason not defines

perl -ple 's/(?<=,)NULL(?=,)//g' inputfile