Cost sharing between group companies in same state or inter state

Concept of sharing here we have ti define for example lets take rent. and Company A recives then rent onvoice in its name and recovers 50% share from company B then gst invoice is must.

Thank you for your reply.
I need help, suppose 5 group companies held in one office. All admin & Overhead expenses cost incurred by only one company & recharges to other 4 other group companies then how to prepare invoice with GST or without GST.
For e.g.
1) Rent Rs. 100000+18%GST = 118000
i want to issue issue Rs. (100000/5 + 18% GST) or
118000/5


2) Electricity Rs. 100000 I want to issue invoice Rs. (100000/5 + 18% GST or
100000/5

You have to issue (100000/5 )+ GST 18%. you cant go under pure agent principle.

Thank you
In case of Electricity also because electricity exempt from GST