You can't use both in the same team. You can't use any of the "same char" in the same team
so no two tenten
no two kankuro (reg+GNW)
no two naruto (reg/sage/tail chak)
no two orochi (sannin/traitor)
etc

It is interesting to note that you CAN have them in survival selection (just not on field at same time)
but not for masuri, which is mostly the same as survival selection.
You also can't have them at the same time on ranked, even in different teams.

Ofc, Pains are different chars, not the same char, just in case anyone asks.