Material movement from one unit to another unit for further processing under gst

Intra state stock transfer require delivery challan

You can send the material for further processing without issue of invoice on jobwork challan without payment of duty but goods should be return within one year.

While returning the material by another unit after process, delivery challan is sufficient or it should carry job work invoice.

As per section 2(68) of Cgst Act, job work means, "any treatment or process undertaken by person on goods belonging to another registered person" but in this case, goods are belonging to same person not another person. So i think, it is not a case of Job Work.
Only Delivery challan is sufficient in this case. As it is transportation of goods for reason other than supply, covered by Rule 55 "Transportation of Goods without issue of Invoice" point (1)(c)