I'm not sure what you mean by routed ports. But those are the main front panel port counts either 24 or 48 on the unit.
In addition there are 4 uplink ports on the right side. Since you are using virtual chassis you can use all four of those for the VC links or just use two per switch to create the VC loop.
Here is the datasheet with a picture.
https://www.juniper.net/us/en/local/pdf/datasheets/1000389-en.pdf
And the virtual chassis cabling instructions for the ex3300