... then on Kangaroo what range should I use ? The range for 135 bits key or the range for 90 bits ?
You still need to use range 135...
This is what the program actually do, if you have
targe key it create N amount of keys arount that key like a target.
Example for -n 10
Subtracted key 5
Subtracted key 4
Subtracted key 3
Subtracted key 2
Subtracted key 1
Target key
Subtracted key -1
Subtracted key -2
Subtracted key -3
Subtracted key -4
Subtracted key -5
All those subtracted keys are near in the range that you select -r or -b