You will need to produce the 6 individual graphs to the approximate size required (use hsize & vsize options) into a catalog (default is gseg). You then need to replay these 6 charts into the final rtf file using proc greplay.
thanks a lot for your answers. I did know proc greplay which is quite useful. I don't know how to create a template so I used v3s in order to have 3 graphs in 1 column. Then, I made some "copy-paste" in word. On word, I asked to present my document into 2 colums. So, I obtained what I would like : 6 graphs on 1 page !