GST for my online Hotel Booking website

Hello All, I am starting my online website which will sale hotel rooms available in 160 countries and will be available for customers to book hotel rooms world wide. (just like booking.com or makemytrip.com but my website will only focus on hotels) Now, I am getting all the hotel rooms from wholesaler (not directly from the hotel) and I will be adding my mark-up and selling them on my website to customers across world. Can you please advise how does GST apply to my business? 1. Customers from India booking hotel in India 2. Customers from outside india booking hotel in India 3. Customers from India booking hotel in outside India 4. Customers from Outside India booking Hotel in outside India. my wholesale supplier will not charge me GST because their HQ is located outside India. SO if GST applies to me then how do I charge my customers? If for example I get hotel room for $100 and sale it for $110. DO I pay GST on $10 or $100? Does the GST apply for all 4 type of customers listed above for all 4 types of booking? or it's only valid for Indian customers booking in India? Please advise. Thanks