PIC32 How do I find group number for peripheral
In my opinion that 'Group Number' parameter is pretty poorly documented.

How I've figured it out is to look at the PPS Pin Selection table for either inputs or outputs (tables 11-1 &amp; 11-2 in your datasheet).
Then, for inputs find the input function or for outputs find the pin you're interested in from the left-most column and then look over to the right-most column of the table.
You'll see they're 'grouped' - so for example:
 - INT4, T2CK, IC4, SS1, REFCLKI are all in Group 1
 - INT3, T3CK, IC3, U1CTS, U2RX, SDI1 are in Group 2
 - etc ...