I don't know what an object it is Piccreader, I suppose you are taught to read a NFC ... for the rest I did the translation
B4X:
Dim CardType(2) As Byte
Dim Atq(14) As Byte
Dim SAK As Byte = 1
Dim sak(1) As Byte
sak(0) = SAK
Dim SN(10) As Byte
Dim scanCard As Int
'piccReader = ??????'
scanCard = piccReader.Request(CardType, Atq) ' ?????
If scanCard > 0 Then
Dim SNLen As Int
SNLen = piccReader.Antisel(SN, sak) ' ?????
Log("SNLen = " & SNLen)
End If