in PIC, one instruction cycle is 4 clock cycles for PIC 8 bit microcontrollers except some high end PIC18 series MCU's.
For delay routines, i suggest to use timers for accurate timing, otherwise using delays in softwares u need to find how many instruction a loop will eat, then
Fosc/(no. of instructions in one run of loop * 4) = single delay time, then u can keep count in loop to run it for that time,
so required delay = single delay time * loop count
hope that helps.