Hello Manoj,
I am assuming tr557 is actually BC557, a PNP transistor, you should not connect a PNP with 12V to the port pin of the 89x microcontroller, since the port pin will sink the 12V through the base, by now your port pin would be damaged or partially damaged, or probably the base resistor has limited the current flow into the port pin.

The uasual way (which I have implemented in hundreds of boards) is to implement the following:

1. Connect +12V to relay coil. connect the other end of the coil
to the collector of a 2N2222A. (ensure that you place a diode
across the coil).Ground the emitter of the 2N2222A, pull up
the base of the 2N2222A with a 10K resistor to the +12V.

2. Connect collector of a BC547(NPN) transistor to the base
of the 2N2222A. Ground the emitter of the BC547. Pull up the
base of BC547 with a 4K7 to +5V (Vcc of the microcontroller).
Connect a 2K7 from the port pin of the microcontroller to the
base of the BC547.

You can also use another BC547 in place of the 2N2222A, if the relay current is small, refer the data sheets of the transistors.

Regards,
John.