Please post the full circuit showing connections with PIC. If you have Proteus then draw circuit in Proteus and zip and post the file. Also post the complete CCS C project files.
I didn't see your code, but the hardware has allready a problem...
What is the relay coil resistance value ?
because from 15V trough R8=100 ohms to get 12V ..
it means maxi current is 30mA
and to drive 6 relays ...
+ 6 leds with about 5mA each => allready consume near 30mA!!
How to drive the relay with 12V
.. check 12V with all relay ON.
there is something wrong !
remove R8 and ZD1 and use a 7812 (12V 1A) regulator (with radiator)
The newly posted PIC schematic still doesn't show clearly where the three serial interface lines are connected. But apparently to PORT D. The code is however operating port B.