Gst consulting for startup in travel business about tax

Dear Sir we are a starup of travel business. We tie up hotels and sell to corporate employees. We tied up hotel for a rent of below 1000 so no gst is applicable. But we charge dynamic pricing to our customers. As you know we deals with corporate all needs tax invoice we want to discuss how we issue an invoice to customer and how much tax % applicable. As example we we charge customer 1200 for accommodation per day. We gave hotel to 999. Our 201 is margin so tax is applicable on 201 as conveyance fee. Please clarify my doubts.