Can any1 tell me how to configure pic16f886 in assembly,to start on power up
Yes. Build the minimal required circuit for your PIC like connections to Vcc & ground, resistor to Vcc - MCLR, then apply power. There are no magical instructions in assembler, BASIC, or anything else, to tell it to start...;o)

Program it, then apply power, and bingo - it starts.