I tried using the below sort card but the sign is not coming in ouput.
BI is unsigned binary, so there is no sign. FI is fixed-point with a sign. For example, an FI value of -1 is X'FFFF' whereas -1 cannot be represented by BI (a BI value of X'FFFF' is 65535). If you want to convert from PD to FI, you can use TO=FI.
can I use the same PS file as SORTIN and SORTOUT?
You can't do that for a COPY operation. You must use a different data set for SORTOUT.