Can cl width be different?Statistics question?

If lower limit is 1 and upper limit is 1200 how do we start writting cles equally divided into 6?The cl width I came up with was 199.83 but I hv to round it to 200 if that is the case median will be different.How to do it.Can I do 1to 200 then 200 to 4oo even if the width bn them is different