I have Brocade Silk warm 3900, 3800 and 3850 switches. I want to know that whether these all models supporting for NPIV or not?
NPIV is supported since FOS5.1 , 5.2 for sure.
Any switch able to run those versions are supporting NPIV, although it may need to be enabled first.
B3850 and B3900 can be loaded with FOS5, thus support NPIV. PLease read the version releasenotes supplied by your vendor.
The B3800 is unable to run FOS5, FOS3.x at most and therefor doesn't support NPIV