There’s a cool speed test tool for Azure at http://azurespeed.com which allows you to test network latencies and speed to Azure data centers from different countries and locations. Along with finding the closest Datacenter near your location, it tests the storage latency to Azure as well as upload and download speeds. This is a third party tool with open source on GitHub.
It clearly shows that Singapore DC has the least latency from Kathmandu followed by West India and South India DCs. So, obviously, when you are hosting your solution in Azure, it makes sense to select Singapore DC when your targeted customers are from Kathmandu. 
The above screenshots is an example of a latency test that I ran from my home location in Kathmandu. Have a look and let me know what you have to say.
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Pradeep Kandel
Public Cloud Consultant | Microsoft MVP | Solutions Specialist (Azure) | Azure Certified | Microsoft Certified Trainer A decade more experience working across various Microsoft products, programs, projects & technologies. Experience leading CoE (Centers of Excellence) for Azure, Microsoft 365, Dynamics 365 & Power Platform among others. Enabler in customer's hybrid cloud, cloud assessment, migration and modernization journey.