I will suggest he should not accept this offer if he is really a BTech person, unless they will give him the right job based on his experience and a comptative salary. If he is not interested to continue in his current position don't let him do the medical or finger print and not stamp the RP. As long as his employer didn't stamp his RP he don't have any ban for coming back to Qatar for another job. But for switching a job with another employer before leaving from this visa he need NOC from the current employer.

If he is really not satisfied with current job (based on his competency) he should not spoil his time with the current job. All the best to him.