I was trying to create an Mean Range Chart with very sample subgroup size which is 1, 3 and 5. Is that possible to have different sample subgroup size in the same chart?
The only Variable Control chart which support variable sample size is the Mean-Sigma chart - search on MEAN_SIGMA_CHART_VSS in the manual. You must use that specific chart type in the manner described in the manual. See the VariableSampleSizeControlCharts example.
Using a Mean-Sigma chart implies that you have a relatively large average sample size, i.e. > 10, compared to an mean-range chart. Under no circumstances should you use a sample size of 1, since the sigma of a sample size of one is undefined.
This is in accordance with "Introduction to Statistical Quality Control" by Douglas Montgomery, a primary reference for the software.