Yes... No more other option. If intra state branches (in any locations) we must file combined details of all outward and inwards details in single... It's applicable to all GSTR returns for the GSTIN...
If intra state and you ll take separate registration under GST then you ll be maintain the books of accounts as Separately... It's mean you can't mingle/ adjust / any GST related taxation to both firms. Maintain separate accounts and returns. No need Tax adjustments to both GSTIN...
Simply said both are not one firm... It's two variant firms....
As per my view., It's not advisable. Bcoz, If you take separate registration as "VERTICAL BUSINESS LINE" then you can't adjust any GST related taxation...
sir if not different business vertical then only one regustration enough since branch is same state. so have to file condolidated return for the signle gstin