Replication Setup what's the value of MySQL auto_increment and offset in my.ini
I'd answer your confusion about auto-increment* variables.

Remember:


auto_increment_increment controls the interval between successive column values.
auto_increment_offset determines the starting point for the AUTO_INCREMENT column value.


So if you're setting 6 servers, you can set them as:
auto_increment_offset=1,2,3,4,5,6
auto_increment_increment=6

so on each servers insertion series will be like:
1,7,13...
2,8,14...
3,9,15...
4,10,16...
5,11,17...
6,12,18...

Idea here is just to generate unique auto-increment numbers.

BUT WAIT!!!!! 

Before you begin, when you say 6 servers it will be pair of 3 master-master or are they slaves of original master? If they're slaves, are they going to accept writes (not good!)? Are you going to write on all nodes (in case of master-master?  The architecture isn't clear enough and hence your solution of auto-increments might not be right / required as well.

Anyways... I hope we fixed the confusion of auto-increment. Trust the documentation and don't get confused by too many articles.