Indian GST Setup in Multivendor WooCommerce Store

Hello, I'm creating a multi-vendor marketplace on WooCommerce. I have used the WCFM Marketplace plugin. Everything is working fine. But I got stuck at implementing GST as a tax in my marketplace. Indian GST calculation should be like this: Seller and Buyer in the same state than total 18% IGST will be applicable. Seller and Buyer are in a different state than 9% CGST + 9% SGST (Total 18% GST) will be applicable. We have to do this for all GST slabs and based on seller state. Is anyone here who has done this type of work already? Indian preferred to hire. Write "GST Fix" in the beginning so I can verify that you have read the whole details. The budget is not more than INR 2000. Thanks! Rutvik K.