GST and Taxation in India for Foreign Income

Hi ,

I am an individual Consultant planning to provide software development services to a company based in Thailand. There is a contract between the company and myself and a monthly invoice rate is agreed. Since I am new to this, please clarify the below questions :

1. Do I need to have a GST?

2. For what amount I should raise in my monthly invoice? Or what will be percentage of GST?

3. Company will be deducting local taxes as per Thailand law , so how much will be my tax in India?

4. Do I end up in paying taxes in both countries? 

Thanks,

Vinod