Sale of part of Imported Goods in Trnasit - Goods and Services Tax - GST

We are registered at Rajasthan. We are importing goods at Nava Shera, Mumbai. It is a container load (10000Kgs). We are taking delivery at Nava Shera and goods are dispatched to Rajasthan. During transit, part of goods are sold and offloaded (3000Kgs) at Mumbai and rest goods (7000Kgs) comes to Rajasthan. For goods sold in Mumbai, we prepare an invoice from Rajasthan charging IGST. For remaining goods, we are preparing a delivery challan from Nava Shera to Rajasthan. In light of above, please let us know : Whether the process adopted is correct? Can we sell imported goods in transit in Mumbai and bring balance to Rajasthan?