Having no idea what type of relay you are using, the following may not apply to your specific application.
A 67N needs one of two polarization sources: In or 3V0. The element also needs 3I0 as an operate quantity.
The use of only 2 VTs will filter out V0, so you either need to get a third VT or you need to use In as your polarizing quantity.
The operate quantity, 3I0, can come from the residual connection of 3 phase CTs or it can come from the output of a single CT around all three phase conductors.
3V0 as your polarizing quantity can be calculated in a numeric relay if you provide the relay with 3-phase, grounded-wye/wye connected VT secondaries. For a single function 67N, the 3V0 will have to come from VTs connected grounded-wye/broken delta. These can be axillary 120-120V VTs connected to the secondary of grounded-wye/grounded-wye main VTs or they can be VTs with the primary connected to the line. It is also possible to get VTs with two secondary windings so that you can connect one secondary grounded-wye and the other secondary broken-delta.
The instruction manual of the relay you intend to use will provide much additional useful information about the application of the relay.
If you are in the ANSI world, as your voltages suggest, I would advise sticking with 5A CT secondaries unless you have some specific application need to use 1A secondaries.