There is no data entity available for the below-
1) Creation of GST reference number sequence group
2) Mapping of Number sequence code with GST reference number sequence group

These are base functionality available and data entity is must as location wise number sequence needs is the primary requirement among the Indian organizations and without data entity the same is very tedious task to configure it manually.
Category: Tax
Under Review
Ideas Administrator

Yes, Agree this is pain for user to setup so many number sequences. It can be address through DATA entity. 
We will consider it for future through DCR.