Stepper motor not returning on its original position

[MarkT]

@ausajid

i have code which is working fine but the problem is when the motor rotates it loses its position and after every cycle it is getting off the position.

Then its probably not fine

Anyway you almost certainly need speed ramping for you motor (unless its ultra-tiny, which NEMA17 isnt), and you've not speed-ramped the pulses so it miss-steps and stalls etc.

The AccelStepper library allows automatic speed ramping and simplifies this greatly for you.