MAIO is usually defined per TRX, so ust one value “6” is weird.
HFS : it is the list of frequencies on which the TRX is hopping. Each TDMA Frame, the 8 consecutive TS are using another frequency from the list.
MAIO = 6 means the TRX starts the hop sequence at the 6th frequency in the list (= 22). The start = when the cell is turned on. Point is that each TRX in the cell should use a different MAIO, so that the TRXs are always using a different frequency (because they are all synchro and using the same HFS, in the same order).
The “order” I am talking about is called “HSN”.