Reroll 1 and 6 in a d6 once

I am trying the ro, but I can't use it from multiple results, here is an example of what I want to do: /r 1d6ro1ro6 Any ideas?

The basic dice roll mechanics have some shortcomings and there's some things that just aren't possible - this is one of them. There's simply no way to do that, without a Pro subscription (which lets you use an API script). You could set up a rollable table to simulate the roll, though that will just show the final output (2, 3, 4 or whatever) and won't tell you if you had a reroll. That is, if you want to use the result as a number and add it to something. Some dice mechanics are just impossible or very difficult to represent on roll20. The best approach in this case, is to just manually roll again when you get a 1 or 6.

The reroll once modifier can handle multiple numbers but only high-end/low-end ranges using the > or < modifiers. So to make it work you have to put 1 and 6 together, which can be done with the modulus (%) operator. So in the following /r ((1d6cs1cf2ro<2 +4)%6+1) 1 & 2 get the rerolled once treatment but the mathematical operations would convert those values into 6 & 1 respectively. The remaining 3,4,5,6 become 2,3,4,5. So all numbers are represented and the 6 & 1 are both marked as reroll once. Note this only works for 1d6 and not higher amounts of dice.

That is a clever solution, though it means the values shown on the dice you roll are different from the reported result (which is even worse if you use 3d dice).