as pix has already explained to you but still i am adding some details.
2+2+2 is the BTS configuration and this configuration deepends on your available freqencies N better available hoping freqqencies.You cant configure your BTS according to your needs but you have boundations. say for example you have 10 frequencies in hoping so there are total 13 freqencies(10+ 3 BCCH freq.)so now the max no of total TRU in all 3 sectors cant be more then 13. you can choose the different sets as 4+4+5, 5+5+3,3+3+7 etc.
I too dont know 1+1 hot standby,
it might be releted with the micros with 2 sectors but both the sectors same BCCH.
Please let me know if u get the answer for this hot standbye?