Arpan,
Within your site, you have 3 cells, all using the same frequency list. Is it correct ?
Then you should use the same HSN for each cell, but with different MAIO. That will create a clean hopping sequence for each TRX with no risk of collision.
On the opposite, if the HSN is different, you are running the risk of getting cyclic interference, when two TRX from different cells are randomly using the same frequency.